I've noticed a few ads that I guess are site targetted. The main clue is that they relate to a general theme of the website (eg: they advertise "widget warmers") but aren't relevant to that particular page (eg: they appear on a page about installing plugs for electric widgets). What I've noticed is that all the likely-CPM ads seem to appear in the ad blocks that I've set up as having 2 ads - horizontal or vertical. I haven't seen any of these ads appearing in the bigger towers. This may simply be a coincidence, but it raises a question...
What are the best ad formats (if any) to maximise revenue from site-targetted ads? Any ideas?
