A side comment: while blocking ads might reduce revenue for sites, it also means the advertiser has to pay for views by people who wouldn't click on the ads anyway.
Oh, and before you scream at me, what about people that simply disable JS, which is basically how all of this works anyway.
I'm not entitled to a free web, I get that, but ads are a failing revenue model due to years of sustained abuse, and that damage is not going to be reversed ant time soon.
However, the need for a list of contractors for works is also required, but things like yellow pages is sort of dead, and if you offer services - eg. you're a freelance photographer, designer, etc. - you need to make yourself visible somehow.
Ads which take the form of an <img> tag pointing to an image hosted on the same domain, aren't blocked (at least in my experience).