Update for those asking if he really pays:

I registered for dollarrewardz as there aren't any tasks yet on tasks4dollars and worked me up to the minimum balance of 2.50$ for a BTC withdrawel, which took me about 4 hours (raw time working on tasks was maybe 2 hours rest was clicking and waiting for them to be available). At 2 P.M. local time I requested a payout. At 4:30 P.M. local time 0.02 BTC reached my wallet.

I also did some research on crowdflower. Their system can be outlined as follows: They offer their network to people that need work done, those people pay them and create tasks. People hosting websites can create so called task channels to offer those tasks to their visitors who get paid by crowdflower for completed tasks. How much a site owner opening a channel gets or how much those who create the tasks have to pay to get them done is not disclosed on crowdflowers site.

All in all I have to say that I am looking forward to tasks becoming available at tasks4dollars because that site is a lot better structured and hopefully will stick to offering only PTC ads and crowdflower tasks. I don't want to be rude but allthough it works, optically dollarrwewardz is quite the mess and has way too many different offers and offer providers.