A few years ago I was abruptly kicked off of Google Adsense with very little explanation. If you search around the Internet you will find that it is a pretty common occurrence. Since Google is the number one name in the game of CPC advertising, they really don't care if they lose a few bloggers here and there. They also don't offer any live support with real people you can talk to to try to get re-instated. In short, once you get booted from Adsense you are screwed!
Since then I've been trying to find a decent alternative to Adsense that pays as good, and I just haven't found it yet. The last article I wrote on this subject was about Technorati Media ads, and that was back in 2012. I also wrote about Media.net which operates the Yahoo/Bing advertising network, but their ads look like crap. Neither of those has performed even half as well as Adsense.
Well I started using Amazon's new CPM advertising system on top of my Amazon Associate affiliate links and I'm now starting to see some decent revenue. It's still not as good as Adsense, but it's doing way better than Technorati or Media.net. If you are making money from Amazon Associate links, then adding their CPM ads to your site will give you some good supplemental revenue for sure.
So as of now, my pick for the best Adsense alternative is Amazon's Associate network mixed with their CPM ads!