I have one space where I can put or a text banner of 250 x 250 or to put there a banner block of 200 x 90? Which one do you think will get me more revenue?
That's like asking, if I wake up tomorrow, what's more likely to happen -- will I get hit by a car or win the lottery? How should we know? Just try both for a week, one at a time, and see what happens.
Dude, I don't think you get my point. Since you only have two options, all you have to do to get a difinitive answer is to test one on your site for a week, then test the other one on your site for another week, then compare the results and use the one that pays the most. I mean, that's not an opinion, that's the most sound advice you'll get. How exactly is getting 10 opinions from 10 people whose sites are nothing like yours going to help you? The only person who can exact scientific data is you, by actually trying one format than the other. But whatever. I've tried my best, you can do whatever you want.
what works for one many not work for other so its better to experiment with your ads. But many guys have reported that large rectangle at the top of the page gets maximum revenue in general.