That's where I'm torn. I want my navigation and search box to be easy to find and to be before the fold. But I suspect that more people will go on to another part of my site thorugh the search. Hopefully they will find ads that interest them on the new pages they find. One thing I like about having my own search rather than using something like a google search that searchers will only find more pages on my site.
Do you know if we can put adsense on a search results page other than the Goodle search?
Anway I will take a careful look in a couple of weeks to see if the search box has hurt my earnings.
I need to look at the long run too. The more people look through my site and discover all I have to offer the more likely they will come back and tell others about the site. I get a lot of referrals by word or mouth or mouse. ;)