Users and annoying ads

The more relevant is a banner, the less annoying it is. A study released by the Ponemon Institute explains that 66 percent of surveyed Internet users would find relevant adds less annoying, and 52 percent would be more likely to click on a relevant banner.
Further details about the research are reported in an article on ClickZ, which also explains that users are willing to give away personal details in exchange for targeted banners.