AdSense vs. flattr, Ads vs. Donations – What’s Best? You Decide!

Not long ago, ContentSphere saw a comeback of GoogleAds. I just wanted to give them a serious second try. Yet, now it gets a new twist. As you can see, I also added flattr buttons for the entire blog as well as separate ones for each entry. I'm having two additional streams of revenue. Maybe I should replace the term "streams" by "drops". What's the best choice to achieve better revenues?