I see frequent posts on webmasterworld.com: 'My AdSense revenue/EPC/eCPM is/are down, what's going on?' - the conversation often degrades into a slam session asserting that it's all a conspiracy or the phases of the moon may be factor - so, I've been thinking of some of the things that a webmaster can control, and those that can't be controlled.
Here are things I have discovered over the years: It is important to focus on the things that you can control, and not worry too much about the things you can't control directly. I find it more productive to focus on the things that I can change, rather than dwell on something totally out of my reach, such as Google's motives or need to increase this quarter's profits.