While Google is without a doubt the most popular of all the search services, a new study conducted by Compete Inc. says Yahoo is doing the best job from a "search fulfillment" standpoint. There are roughly 7.5 billion search queries performed every month in the US. However, there are only about 5 billion search referrals every month which, according to the study, means that roughly one third of all searches go unanswered.

The survey found that 67% of all searches in August were done using Google, but only 65% of those prompted a user to click on a result. Yahoo, on the other hand, accounted for 20% of all searches in August, 75% of which resulted in a referral.

Compete makes an interesting argument on search effectiveness - not a flawless one, though. In reality search effectiveness is much more complicated than that. Matt Cutts, head of Google's Webspam team, noted on Compete's blog that sometimes searchers get answers from the snippets that appear on Google's results page, doing away with the need for users to click on a link, while on Yahoo "you don't get any OneBox answer, and the snippets are unclear," he said. I, for one, prefer Google, but regardless of which engine is more effective, it is interesting to look at it from different perspective.