I've looked at: adbrite, adroll, tribalfusion and a bunch of others after asking HN if I should go and make an inventory of advertising networks and how well they perform relative to each other.
None of them comes close to adsense in terms of performance (and adsense absolutely sucks, if you can get $1.00 ECPM out of adsense for a large volume website then you're very very lucky), so even if they would handle customer service better than google (most of them don't) they would still be pretty bad income wise.
You should try to find vertical ad networks, these are the ones getting the higher ECPMs ($5-$20). I run a couple programmer focused networks, but there are networks out there for just about anything. Here are some off the top of my head:
Is that $1 ECPM for the whole site, or just one ad spot? I mean, for the whole page, which might have up to five google ad spots, or just one spot, or channel as google calls them.
ECPM per channel on large volume typically is 16cts.
So if you have multiple ad spots on a page you might increase that a bit but it's not like two adspots work out to 32 cents, the amount per spot goes down as the number of spots goes up.
I have some sites that do around 25 cents eCPM, most of the time I wouldn't bother with a eCPM that low... $1.50 or $2.50 is more like what I want.
I've got a project in the pipe that I'm projecting about $2000/month in ad revenue... That's based on an extrapolation from a series of smaller projects covering similar domains. Both my black hat SEO friends, legit "Web 2.0" people and people who are experts in this subject domain would all think I'm crazy, but that's exactly why I can pull this off... Nobody thinks this will work so ranking for this is like stealing candy from a baby.
Unfortunately, the average webmaster is drawn to low-eCPM topics like a moth to a flame... That's their loss.
None of them comes close to adsense in terms of performance (and adsense absolutely sucks, if you can get $1.00 ECPM out of adsense for a large volume website then you're very very lucky), so even if they would handle customer service better than google (most of them don't) they would still be pretty bad income wise.