How Search Engines Rank

I work for a company called Efficient Frontier. We manage almost $250 million in paid search advertising - by some accounts that's about 1.5% to 2% of all US paid search. Not too shabby. So, we've got a pretty good handle on traffic, we have lots of aggregated data, and we get a good overview on what's happening with conversions.

In the month of May, here's how well various websites performed - in terms of driving transactions (the ultimate measuring stick).

• Search Engines rank this way: Google, AOL, MSN, Ask, and then Yahoo! (kind of surprising, huh?)
• Google content is about a 1/4 as effective as Google search (not too surprising, but maybe even higher than I would have thought)
• Shopping engines are very effective in delivering good clicks (remember, these are syndicated listings on their page)
• Other comparison engines also work very well (kayak etc) on syndicated ads