From my own analytics observations, I’d have to say Hitwise’s results are almost dead on. I don’t have the adequate data to compare identical campaigns in alternate search engines outside of Google, Yahoo, and Live.

My figures more or less agree that Google yields nearly 3-4 times the traffic of Yahoo, with Microsoft near insignificant. Not to say the smaller engines aren’t profitable for some, but for most their sample sizes are really too small to trend any traffic.

Garry