You are in fact hurting not only the site owner but also all AdSense participants if you are clicking just as a "favor." Meaningless clicks don't convert, which means that the advertiser in question is not getting any value by having his/her ads on the site. Advertiser may eventually give up on AdSense altogether if there are too many low quality clicks. Remember: it's a very simple matter for an advertiser to opt out of the AdSense system, and instead opt to advertise next to the Google SERP's exclusively. Bottom line: clicking as a compliment = click fraud. Yep. As always, IMO.
I click too ,cos i trust more payed ads and to suport the webmasters and motivate them to make their sites more usefull
I do click, when I got interested on the ads. Not because I want to give the webmaster a favor or something. That's the principle, "You click on Ads because You as a consumer got interest on it"
A month ago I was clicking on ads if I liked the website. Then I realised that somebody have to pay, so now I'm only clicking ads I'm interested in. And I'm interested quite often.