We are proud that Google has interviewed us for a showcase profile. Google has been especially interested in the way we are tracking "conversions" in our campaigns.
As I have said more than once, search advertising is different from traditional advertising. You need to take a very analytical view, otherwise your money goes down the drain. An the most important metric is cost-per-conversion, in other words, how much is it costing you to acquire each client.
So far, so good. The tough question is how to do it in the site. Conversions happen deeply inside the site (after visiting 4-5 pages usually), and it is not that trivial to tie the two. We have devoted a large effort to this, and it has given us a great tool.
If you want some help with this, go ahead and contact us, we'll be glad to help.