For too long, data that is essential to the practice of search engine optimization has been inaccessible to all but a handful of search engineers. The connections between pages (links) and the relationship between links, URLs, and the web as a whole (link metrics) play a critical role in how search engines analyze the web and judge individual sites and pages. Professional SEOs and site owners of all kinds deserve to know more about how their properties are being referenced in such a system. We believe there are thousands of valuable applications for this data and have already put some effort into retrieving a few fascinating statistics:

Across the web, 58% of all links are to internal pages on the same domain, 42% point to pages off the linking site.

1.83% of all links on the web are nofollowed and of these, 61% are external-pointing, while 39% link to pages on their own site. While those percentages may seem small, that's a massive number (~2 billion links) that are leveraging nofollow for link juice "sculpting."

While 0.08% of pages on the web use the 301 redirect, 0.12% (nearly twice as many) employ 302 redirects. Another 0.005% use the meta refresh.

About 1.5% of all pages use the meta noindex tag (which is a lot of content the engines don't get to see) and 0.87% of all pages use the meta nofollow tag.

From our entire index of pages, the median page received about 77 links (both internal and external), while the average page gets 32. If your pages have more than 32 links, congratulations! You're above average :-)

Over time, we hope to answer hundreds of questions that the major engines, due to their penchant for secrecy, have kept under wraps. We'll also be offering custom data reports for companies that would like to retrieve more specific information from our index.

The other announcements include a link analysis tool called "Linkscape" and a redesign of the SEOmoz site.