Talk about your valuable statistics! Traffic from different search engines most certainly yields different CTR. The reason Froogle is the highest is pretty obvious– people searching Froogle are actively in search of buying a product.

The reason for the other search engine CTRs is highly speculative, but I personally believe it has a lot to do with the sophistication of the searcher. MSN comes as the default page for Internet Explorer on all Windows browsers, and (in my opinion) people who leave their default page to MSN are probably not as savvy net surfers as those who do not.

The big question for most reads might be, “Why is Google’s CTR so low?” I personally believe that the answer has two parts:

1. Adwords. Often the same AdWords ads that appear on search engine result pages for a set of keywords will appear on the pages that are in those results. This is true since the content is very similar (which is, after all, why they are in those results). If a searcher is going to click on one of those ads, he has a good chance of doing so on the search results page before he ever reaches your page.

2. Google searchers tend to be more net savvy than other searchers. Google is often hailed as the “Computer Geek Search Engine”, and those who pride themselves on being up on technology like to use it. Those who are not “Geeks” but still use Google do so because they have become net savvy enough to know that, at least for now, Google still offers the most relevant search results. These kinds of individuals are quicker to spot the difference between an on-page link and an advertisement.

Finally, the reason for the non-English Google search traffic not doing so well is quite likely the language barrier.

Do not focus all of your search engine optimization efforts on Google. In fact, focus more on MSN and Yahoo, since they get a huge percentage of search traffic as well and they perform much better than Google does in generating ad clicks.