I really, really don't buy the idea that I should feel bad for using adblock. The whole "ads can be a way to provide quality services, and adblock removes that revenue" is the marketer's equivalent to the {MP|RI}AA's "every pirate is a stolen sale". The whole thing with the Internet is about desintermediation, and marketing departments are nothing but middle-men between producers and consumers. Even worse that they a…
There are two main difference between the RIAA "every pirate is a stolen sale" and adblock.
1)When you "pirate" something it doesn't mean that you "pirate" everything, while if you install adblock you block the ads on every site.
2)When you "pirate" something it doesn't mean that what you have pirated would have been a legal purchase. But if you go to a website you would have gone there with or without ads. You can say that you won't have clicked on the ad or won't have purhcased anything. But almost 99% of our ads revenue is on impressions and not on click or conversion, so it doesn't really matter if you click or convert the ad.
But, right know, the number of people that use adblock are not that big of a deal (at least on our niche market) that you have to work on fighting it because, right know (for us), it is not worth it.