tedster - 10:00 pm on Aug 5, 2010 (gmt 0)
With any conversion, it's been common to "give credit" to the page that directly generated the conversion. This is now being called "last touch" attribution.
In many cases, such as running several marketing channels, or working over an extended sales arc as is common in B2B, you really get a lot of actionable intelligence from "first touch" data - how this new customer first discovered you.
Setting up first touch tracking can be complex - but it's getting better as more vendors learn to support it and more people share their approaches. If you search Google for the phrases [first touch attribution], [first touch tracking] and so on, you'll find lots of details.