My company runs a few content sites that are primarily monetised through advertising. They're not small as in "some guy updating them in his free time", but they're small as in a few paid members of the editorial team, a few million pages a month. For us, yes, advertising is the difference between us being a profitable company and us not being a company at all.
That said, a.) we are doing OK before this adblock change and b.) our adverts don't fit what are being defined as "acceptable" here. We do make sure we never get too obtrusive, we don't do automatic playing videos, we don't do roadblocks, we don't do anything with sound, we don't do anything that covers content or expands when you mouseover... but some of the banners we serve are flash with basic animations. We, and the majority of our users, are happy that this is a good way to advertise without letting it become an annoyance, but we wouldn't make it onto ABP's whitelist.
I also have a few entries in my /etc/hosts ...
127.0.0.1 googleads.g.doubleclick.net
127.0.0.1 ak.p.openx.net
127.0.0.1 tags.expo9.exponential.com
127.0.0.1 resources.infolinks.com
127.0.0.1 resources.intextscript.com
127.0.0.1 kona.kontera.com
Google ads was simply responding too slowly. Too many pages were not rendering correctly or at all, pending a response from them. That's probably the fault of web authors not embedding the Google ads correctly. But not to worry. Now I just see error IFrames.As for the others, the damned double-underscore spam links were getting to be just too annoying while reading text — especially the ones that would react to mouseovers.