These are on my wife's IOS devices. I've played them casually. It gets tedious.I loved the original Angry Birds and Rio; played them to death. Space seemed to lose it for me, I am finding that most of the levels are about figuring out the absolute perfect angle to make the shot at. Just lost some of the "fun".
Downloads != copies sold. Many people download multiple copies because they have multiple iOS devices. I let my iOS devices automatically sync and thus they automatically download. If I buy an app on my iPhone, it shows up on my iPad, and my wife's iPhone via downloads. Thus for every app I buy I download it at LEAST 3 times.