An interesting report (pdf)< http://www.webmasterworld.com/rv4.cgi?f=20...shing_works.pdf > has been published by authors Dhamija, Tygar and Hearst entitled "Why Phishing Works". Apart from being interesting reading in itself, the authors note that if websites contained professional-looking ads, they were more likely to assume the site was legitimate (this also applied to other page elements).

The relevance of this to adsense users?

It is sometimes a concern that putting ads on a (legitimate!) site will reduce the perceived quality of a site--that somehow the site has been hijacked by the webmaster who wants to make a quick buck. (Whereas we're innocently just monetizing our websites, of course!) But this research seems to indicate that with careful page design and intelligent use of ads, the perceived authenticity or authority of our page content may actually increase.

Interesting, huh?

I personally am not going to belive a site is legitamate just because they have professional looking ads. Anyone can make "professional looking" ads with a little practice and some can just lead to other sites. Ads really in my opinion do nothing for me except to show that the person is hoping to make an income or to help pay for the site for them and they are seen regularly around the internet now that who knows what to believe or not.