Why Searchers Don't Go Past the First Page. Or the first half of the first page.
We've seen lots of data about how searchers process search pages. The current rule of thumb is that 50% look at the second page of search results, and 25% at the third page. And almost no one looks at any other pages.
This is probably true, as far as it goes. I believe, however, that there are two kinds of searchers, one of whom is not usually discussed.