To boost its new push into the rental marketplace, Zillow's paying $40 million for Rent Juice, a San Francisco company that makes software that landlords use to manage their properties.

The deal follows Monday's release of Zillow's mobile application for searching rentals, which provides estimated rental values and search services.

Rentals are the latest segment of the real estate industry to which the Seattle company is extending its search, mapping, advertising and services business.

"The acquisition of RentJuice, with its talented team and innovative solutions for rental professionals, propels Zillow's rental marketplace ahead by years," Zillow Chief Executive Spencer Rascoff said in the release.

It's the third acquisition for Seattle-based Zillow, which also today reported record earnings in the quarter that ended March 31. Its sales grew 103 percent to $22.8 million and profit swing to $1.7 million, up from an $800,000 loss during the same period last year.

Monthly unique users of Zillow increased 84 percent to 31.8 million during the quarter. Growth on mobile devices is especially strong, overtaking Zillow usage on the Web. In March 155 million homes were viewed on Zillow mobile apps, or 57 homes per second, the company said.

Rent Juice started in 2009 and has 31 employees. For prices starting at $59 per month, it sells subscription marketing services, including a mobile app that landlords can use to manage their listing database, update photos and interact with prospective tenants.

A spokeswoman said there are no current plans to relocate the Rent Juice team. Asked if any layoffs will result from the deal, she said via email that they're planning on "status quo. No major changes."

Inspired by our local space explorers, I donned my high-tech prospecting gear and set out to mine precious nuggets of wisdom from a nearby star.

That would be Rich Barton, the startup wunderkind who founded Expedia as a twenty-something Microsoft manager, spun it into the world's largest travel business and became a serial entrepreneur.

Barton went on to co-found Zillow in 2005 and became a venture partner at Benchmark Capital, the Silicon Valley venture-capital firm that owned 20 percent of Instagram before it was sold earlier this month to Facebook for $1 billion.

From Barton's perch, at least, it looks like another tech boom is under way and money's flowing like the old days, back before 2008.

Barton shared this view -- and tips on how to start and build big companies -- last week with the local chapter of The Indus Entrepreneurs. Here's my edited trove from the event.

On today's climate for startups: "It's pretty frothy. It's a great funding environment, great for the entrepreneurs. There is a ton of money chasing good people with big ideas. It's as snap, crackle and poppy as I've seen in more than a decade. There are lots of exits happening, there are lots of companies going public right now, there is a reasonable amount of [merger and acquisition] activity that's going on. If the market holds up, we're about to enter a phase of serious IPO activity.

On demand for new tech stocks: "The public market, buy-side guys -- the guys who run the mutual funds, the technology-oriented mutual funds -- are starving. They've been starving for a decade for product to buy. It's kind of been fashionable, if not convenient, for companies to not go public, and all of a sudden everything's coming public. I think we're going to see a ton of activity."

On making mistakes: "I think the great skill of the entrepreneurial mindset is the ability to forget mistakes. Learn the lessons from the mistakes, but forget them and not obsess on them and not let your mistakes undermine the confidence you have around the dreams you have. I think that's a big thing."

On spreadsheets: "I tell you, the spreadsheets never work out the way the entrepreneurs and the venture capitalists think they're going to work out. We all know that. ... Rarely does the company end up being what the original idea was anyway. So you've got to have people on the boat who can figure out how to change the fly, put something new on there and be creative and figure it out."

Pitching stories, not numbers: "I'm a PowerPoint guy, not an Excel guy, put it that way. I think people that come in with lots of projections and Excel spreadsheets at very early stages doesn't necessarily bode well. ... It's very difficult to plan the unplannable, so I look more for passion around a story and idea than I do around a spreadsheet."

Mobile, mobile, mobile: "If an entrepreneur comes to me these days and gives me a demo of a website and doesn't demo something on a smartphone, I almost out of hand am not even interested in it, because that shows an unbelievable lack of understanding of how people are actually interacting with the Internet now."

Traffic before revenue: "All of my businesses -- I look for getting a mass-engaged audience first and worrying about a business model second. Expedia was that way, Zillow was certainly that way. ... Get the masses in first, then figure out how to monetize."

On changing course: "Pretty much everything I've been involved with had some kind of pivot. Zillow had a really big one. We had raised money -- my guess is, we had raised $20 million -- before we even figured out what the product was going to be. ... We actually thought the way for perfect price discovery in real estate was going to be auctions."

On raising money: "The whole venture-capital business is one that operates a lot on personal networks that have been established. For people who are trying to get plans in front of me, the best way ... is to have somebody who I know really well and think is smart tell me to take a look at something."

Capital in Seattle vs. Silicon Valley: "There's plenty of money up here. There's a lot more down in the Valley. ... I find that the Seattle startup ecosystem is a few steps behind but on the same path as the Silicon Valley ecosystem."

On Gates and Ballmer: "Bill Gates and Steve Ballmer were my venture capitalists at Expedia. I kind of thought of them that way. When I pitched the idea of Expedia to Bill and Steve, I tried to get them to fund me on the outside. Honestly, I said I want to start my own business and said look, this is a travel business, not a Microsoft software business. They kind of laughed at me and said, 'Who are you going to hire?' But what they did say is look, you may be right, let's get this going internally and if it makes sense to spin it out, we'll think about it."

On spinning off Expedia: "You know, huge credit to those guys: When it came time ... I came to them and said, 'Look, Expedia is on the brink of becoming something huge and interesting and important. If we stay at Microsoft, it will not be. If we spin it out, it might be.' And along with that I asked for $100 million to spend in marketing. Steve Ballmer was my boss at the time [early 1999]. ... He said, you're not getting $1 million from me to market. I said, 'Well, you know what, the public markets will give me $100 million, and they'll give it to me really cheaply, so let's go do that -- let's take the public market's money and turn this thing into something real.' And he said OK and we did it. It was a grand experiment for Microsoft.

"Microsoft has not done anything like that since but it obviously worked out -- it worked out quite well. Expedia was half the size of the largest player in the space when we spun out. Within 18 months, it was twice as big as the No. 2 player."

What's needed to take the startup plunge: "Courage. Think of 'The Wizard of Oz.' We've got the Cowardly Lion, the Scarecrow and the Tin Man. My kind of view of great entrepreneurial leaders is courage for the Cowardly Lion, you've got to have brains for the Scarecrow and probably most important is, you've got to have a heart because you cannot attract people or capital without a heart. People respond to passion; people respond to real feelings, real emotion, things that really matter."

His busy schedule: "When you have eight jobs, it turns out nobody knows when you don't show up to work."

Seattle real estate startup Zillow today updated its initial public offering prospectus, adding sales information from May to the document that it filed last month.

Apparently it saw a 10 percent increase in traffic last month and it's adding the better numbers to investor pitch.

Here are the high-level stats in today's filing:

Consumers increasingly are turning to the Internet and mobile devices for real estate information. During May 2011, 22.0 million unique users visited our website and mobile applications, representing year-over-year growth of 102%. We operate the most popular mobile real estate applications across iPhone, iPad, Android and BlackBerry. During May 2011, Zillow was used on a mobile device more than 8.8 million times, with more than 1.7 million homes viewed on mobile devices each day.

For comparison, here are the stats in the May 23 filing:

Consumers increasingly are turning to the Internet and mobile devices for real estate information. During April 2011, 20.2 million unique users visited our website and mobile applications, representing year-over-year growth of over 89%. We operate the most popular mobile real estate applications across iPhone, iPad, Android and BlackBerry. During April 2011, Zillow was used on a mobile device more than 8.5 million times, with more than 1.7 million homes viewed on mobile devices each day.

Finally, after dropping all sorts of hints, Zillow is taking formal steps to go public.

The company hired Citigroup to handle its initial public offering, according to a Bloomberg report citing three unnamed people with knowledge of the plans.

There was no information about when the IPO would take place, but the implication is later this year.

Zillow was started by former Expedia and Microsoft executives and became one of Seattle's best-funded consumer Web startups in the last cycle. Bloomberg noted that a $30 million round of financing in 2007 valued Zillow at $400 million.

A spokeswoman and Zillow's chief executive declined to comment.

Maybe they should talk to PopCap Games, another Seattle consumer company that's been candid about its plans to go public later this year.

Zillow is adding a new tool that could extend the real estate website's appeal beyond buyers and sellers of homes to renters and landlords.

The company is adding estimated rent prices to the more than 90 million U.S. homes and apartments listed on its site.

"Rent Zestimates" builds on the site's marquee feature, the home value estimates that it calls Zestimates. It also ties in to a rental listings business that Zillow started in late 2009, upping its competition with newspapers, Craigslist and other classified advertising services.

I guess they didn't like Restimates, Zent or Zentals.

Zillow included cautionary notes in its announcement, making it clear that it's only estimating rents.

It said the estimates "can be used as a starting point" for determining a home or apartment's monthly rent price. The estimates may help renters get a fair price before signing a lease, when used "in combination with additional market information on rentals."

There's no doubt some renters will haggle after a quick check of the estimates, and landlords will look to see if they might adjust rents.

Zillow is expecting repeat traffic; it noted that 70 percent of people who move each year are renters, according to a 2009 Census housing survey.

I'm guessing the biggest users will be fantasy real estate players. It gives them factoids to consider when they're imagining whether to rent or sell, buy and rent, or maybe rent a nicer place.

It's especially easy to play virtual landlord when you combine the rent estimates with other information that Zillow generates. You can get a quick idea of a property's value, mortgage payments and rent, to see if it pencils out as a rental.

"Buyers and renters are not exclusive categories -- many people are considering both options when shopping for a new home. Similarly, many would-be sellers in today's housing market are considering whether to become landlords rather than sell at a loss," Zillow Chief Executive Spencer Rascoff said in a release. "We created Rent Zestimates to empower people with information and data to make the right real estate decision for them."

Zillow, which was started in 2006 by veterans of Expedia and Microsoft, drew 16.8 million unique visitors in February.

Zental prices ... I mean Rent Zestimates .... will also be available on Zillow's mobile apps.

Here are a few screenshots provided by Zillow:

Zillow.com co-founder Rich Barton is stepping down as chief executive of the 5-year-old real estate website, which is positioning itself for an initial public offering when conditions are right.

Spencer Rascoff, Zillow's chief operating officer (left), is taking the top job at the Seattle-based venture.

Zillow simultaneously is announcing that the company is now profitable. It drew 12.5 million unique viewers in August, up 41 percent over August 2009, and its online mortgage quote service is up sixfold, with 314,000 loan requests last month.

Barton said the company doesn't need to raise any more money. Investors have put $87 million into the business, which now has about 200 employees.

"We're profitable now and we have plenty of money in the bank," Barton said. "We could see at some point raising money through an IPO, which would be a desirable event for all of us."

Zillow co-founder Lloyd Frink is also moving, from president to a new fulltime position as chief strategy officer.

Barton, who helped start Expedia within Microsoft and became its chief executive, went on to become a Web entrepreneur and venture capitalist. He'll continue as executive chairman of Zillow's board.

The move frees up Barton, 43, to spend more time on a few other company's he started recently, including travel site TravelPost. Barton said he'll continue to spend at least half of his time with the company.

Rascoff was groomed for the position and has lately been Zillow's highest profile executive.

Looking forward, Rascoff said Zillow's primary goals are to keep extending its reach and brand, grow revenues and build up its mortgage market business. The IPO is still a ways off, but not out of mind.

"We'd like to go public. We'd like to be public at some point. We intend to be public at some point," he said, definitively answering the question repeatedly asked about Zillow's future.

Rascoff, 34, is also a veteran of Expedia, where he was a vice president before joining Zillow in 2005. He joined Expedia after its parent company at the time, IAC, bought the company he co-founded -- Hotwire.com -- for $675 million in 2003. Earlier, the Harvard grad worked at Goldman Sachs and other investment companies.

Barton (left) said the transition has "been part of the plans since I first met Spencer. When I interviewed him it was my hope that he would be CEO someday."

Everyone's been wondering if Zillow would someday hook up with one of the big Web portals.

Now it's finally happening, sort of.

Under a deal being announced Friday, Zillow is going to become the exclusive partner of Yahoo Real Estate, handling real estate advertising for both sites. The two are also combining their listing directories.

Zillow and Yahoo aren't marrying, but they're now in a pretty serious relationship.

The companies run the second and third largest Web real estate sites in the country, according to comScore data they provided. It pegged Zillow's May traffic at 7 million unique visitors and Yahoo Real Estate's at 6.1 million uniques.

Linked together they'll pose a bigger challenge to the category leader, Move.com. Move, which includes Realtor.com, drew 12 million uniques in May.

"For Zillow this is a seminal announcement in our four-year history because it effectively doubles our size,'' said Spencer Rascoff, Zillow chief operating officer.

For-sale listings bought on Zillow will automatically appear on Yahoo Real Estate. Yahoo will continue to handle its own display and search ads sold to companies such as home-improvement stores.

Executives from both companies wouldn't comment on how this might affect Zillow -- Seattle's best-capitalized Web startup -- going public or being acquired someday by Yahoo or someone else.

Zillow and Yahoo Real Estate have had a smaller partnership since 2006, when Yahoo began using Zillow's Zestimate house value estimations on its site.

The sites will continue to look different to consumers, but they'll have the same ads, explained Steve Schultz, head of Yahoo Real Estate.

It sounds a little bit like the join operating agreements that newspapers in the same market used to combine business operations, such as the arrangement that had The Seattle Times handling advertising for the Seattle Post-Intelligencer for 26 years until 2009.

Rascoff and Schultz wouldn't say how long their deal will last, but they expect it to take effect in the fall.

A group of former Expedia executives is dropping bigger hints about a new travel company they're starting in Seattle.

With the buzz they're getting so far, they won't have to spend any of the $9.8 million they've raised on job ads.

Rich Barton first announced the venture with a Tweet in January, saying "Greg Slyngstad & I are cooking up a consumer internet startup. R U our founding CTO? Seeking smart, passionate team-builder."

Barton and Slyngstad worked together on the creation of Expedia within Microsoft in the early 1990s and worked together later when it was a standalone company.

They found a CTO -- former Expedia engineering boss Sunil Shah -- and are now hiring software engineers and managers, including a business development director with travel and advertising experience.

After trickling out hints, the company today filed an SEC report disclosing that "NewTravelco" raised $9.8 million.

A Web site for "New Travelco" lists the team and hints at the business, without providing much detail:

"We believe it is still early days in the Internet travel revolution. The increasing power of transparency, connectivity, and mobility will continue to open new worlds to travelers and new channels for suppliers. We believe that a small, passionate team of people can effect massive change."

Venture firms involved include General Catalyst Partners, Bellevue's Ignition Partners and Benchmark Capital, where Barton is a partner.

Cambridge, Mass.-based General Catalyst also backed travel search site Kayak.com, where Slyngstad is a director.

You'd think another travel company would create conflicts for Slyngstad at least, but maybe the Seattle venture isn't another way to sift through schedules and book trips. Kayak's chief executive told travel business site Tnooz that Slyngstad will remain on its board.

The job listing for its business development director says the job involves building revenue from Google Adwords, so maybe ads are going to be more important to the company than commissions.

I wonder if it's going to be some sort of social-sharing-community site for travelers, maybe a place to share travel videos, photos and messages from mobile devices?

Recommendation systems used by travel sites today are getting long in the tooth and don't take advantage of users' increasing connectivity, mobility and expectations of transparency created by YouTube and social media.

Wouldn't be it nice if you could zoom to a location and see a live discussion of current conditions at a hotel, with pictures and video, instead of wading through the old star reviews from anonymous travelers salted with posts by unscrupulous hotel managers?

Then it would be like Zillow and Glassdoor turned to travel, aggregating user-generated content to create a destination reference and referral site for people researching their next trip.

Zillow's hit mobile real estate search application is coming to the Android platform Thursday, the company announced.

The iPhone version of the application has been downloaded more than 1 million times since it debuted last April, Zillow chief operating officer, Spencer Rascoff, said in the release.

The Android version uses GPS to find and follow users' location and displays Google Street View images of houses, along with sales information and estimated values for 95 million homes in the U.S. It also takes advantage of Android's voice search capability, so users can say an address, neighborhood, Zip code or city to call up that map location.

Zillow is offering the Android app free through the Android Market.

Zillow better watch out: The latest thing to emerge from Google's barrage of launches this week duplicates one of the Seattle startup's most valuable features.

Google is now offering an instant mortgage quote service that instantly connects lenders to buyers, and provides useful tools for comparison shopping. It also instantly estimates house values (a Gestimate?) provided by IntelliReal.

The mortgage rate feature showcases new "comparison ads" that it's launching in a limited test, selling space in free tools that consumers may use before making big-ticket purchases.

UPDATE: Google Maps is also adding Zillowesque real estate info. From the announcement:

First of all, we've made it easier to find real estate listings. Now, you can simply select "Real Estate" from the 'More' button on the top right of any Google Map to discover listings. From there, it's a simple matter to refine your search using the left hand panel - price, bedrooms, bathrooms, and so on. Of course, you can still pan the map to search for the perfect neighborhood and it'll automatically update with more listings.

I wonder if comparison ads will muddle -- in consumers' minds -- the information found by impartial search algorithms and paid placement. It may be handy if you are rate shopping, but it's no longer the results of an objective search engine.

Sound like Google's becoming more of a decision engine. Maybe it's time for Microsoft to buy Zillow before it loses zest.

Zillow today announced that it's partnering with Windermere Real Estate, which becomes the latest firm to automatically feed its listings into Zillow's Web site.

Windermere has more than 30,000 listings and Zillow drew 8.8 million uniue visitors last month, up 64 percent year-over-year, the release said.

Zillow said 37 percent of its traffic comes from the 10 Western states where Windermere operates.

Pet Holdings -- the parent company of cute kitties site icanhazcheeseburger.com -- bumped Zillow off the top of the Seattle Startup Index maintained by entrepreneur Marcelo Calbucci.

Eleven new companies were added to the list of Web-oriented ventures, which now totals 345 companies in the greater Seattle area.

Calbucci said he also removed iLike, which was sold to MySpace, and Others Online, an "audience optimization" company sold to ad venture The Rubicon Project.

Here are the top ten from August:

Pet Holdings
Zillow
BuddyTV
Picnik
CarDomain
Wetpaint
Robot Co-Op
PayScale
SEOmoz
ActiveRain

It's hard to get too worked up about iPhone applications now that jillions are available, but the new Zillow iPhone App debuting tonight is amazing.

It could be one of those bits of software that convinces iPhone holdouts that, maybe, it's finally time to get the hardware.

Especially if they're real estate voyeurs, as two-thirds of Seattle has become over the past decade.