I keep seeing my four ad block (336) go down to one or two that are either mfa's or just plain low paying ads (half of what my ecpm were). Several times over the years I have sent Adsense an email asking them how to opt out of the lower performing ads that replace the four ads in that block. Their response is always the same, these are better performing and better paying ads. It is not true. I keep adding them to my ad filter and at some point when I have a certain percentage of ads in my filter, I believe I trip something that gives me all lower paying ads. My good paying ones don't come up at all anymore. Then I delete everything in my filter and the good ones come back up and the game starts all over again. I've been playing this game way too long. It takes a great deal of time and frustration when my income drops to half. Has anyone been successful opting out of these and how did you do it? Thanks in advance for your help.