I usually get more searches than landings too. It's because a "search" is when an actual search is performed, so if you set up a Keyword, and a visitor lands on a page, that's a search because the lander is a 1-click lander. If a visitor performs another search, it's two searches on a single landing.
As for the earnings, I would say it depends on the kind of traffic that you get. My average CTR is about 15-18% there.
