Just in time for the credit crunch, Amazon's investing in Bill Me Later, a payment service specializing in same-as-cash, deferred payment deals.

It seems like a response to eBay's PayPal and Google Checkout, but I think that's not exactly what's going on. Those services simplify checkout and create billing relationships with customers, which Amazon already does pretty well.

The partnership with Bill Me Later gives Amazon the ability to go further and offer deferred payments, such as 90 days or six months with no payments.

That sounds a little simple, but it's important for Amazon as the financial crisis tightens the screws on credit happy consumers.

If consumers start using credit cards less because they're suffering from higher mortgage rates, fuel prices and general inflation, they'll shop less at online merchants.

Bill Me Later may help fill the void. It's another way to keep the spending going with short-term credit and simplified online purchasing.

For card-wary consumers, it seems like a smaller commitment and a better deal. (It is, if you pay it off in time -- otherwise it starts charging high interest just like a credit card.)

The partnership also gives Amazon a way to offer financing deals similar to those offered by offline merchants, and it gives consumers living paycheck-to-paycheck another way to buy things they really can't afford.