It's less than adsense - about 2/3 - but I've only done limited testing on three different sites and only have a few hundred clicks to get an average. The biggest problem isn't the payout, it's the ad inventory - which is vastly smaller than adsense, so the CTR is about half at best. It has a lot of potential if they can attract more advertisers.
well, want to sign up for adcenter. but they don't take people in the netherlands. and I think they're in beta now. so it's hard to sign up