Thanks, but i meant to this scenrio: i have two blocks of text in page, one about affiliates and the other about bicycles (for example). does the placement of the ads will control it's content according to the relative distance from the blocks of text?
If you have a text block in your top page and your ads are at the bottom of your page, it will still show relevant ads. Just an example...
yes it does matter. try to guess which part of the page does your visitor usually focus on, put the ad there