Bidvertiser works on basically the exact same principles as Google, only reason they're less popular is because they dont have a multi-billion dollar search engine behind them which half the worlds internet using population uses from time to time. Be that as it may bidvertiser still has their market... Any of your sites that are turned down for publication by Google might still be approved by bidvertiser (i'm talking here about the ones that maybe dont contain as valueable and original information as you had hoped, not the adult content/hate speach ones(as a point there really is little use trying to sell ad space on an adult content/hate speach site to anyone other than the owners of that exact site or similar which are probably his too))

I just very recently got Google Ads APPROVED (:D) for this site! Up till then i was using Bidvertiser and have indeed earned revenue from ads on site! I also still running Bidvertiser ads on the 10 other sites/blogs although i am planning of changing over to Google Ads on 2 of them as soon as i've updated them!