Hey everyone, I've also been experiencing a good drop in RPM and CTR's over the last few weeks. Though I was testing different things such as blocking interest based and 3rd party ads. I can tell you for my site, that worked, my CTR and RPM's went up but then about 2 weeks ago, I started to see drops and this week, its continue dropping.
I have spent a lot of time on here researching different answers but what I am starting to see more and more of is unrelated ads hitting my site. I block them, but more and more keep coming up, which is causing CTR to drop which in turn effects RPM.
So for those of you who are seeing earnings (RPM) drop, are you also seeing drops in CTR and take a look at your site, are you seeing more unrelated types of ads.
It used to be where I would spend once every few weeks going through the review ad center and blocking ones and now it seems i need to do it every day.
To make matters worse, in years past, Oct and Nov were times where RPM always would jump up.
One more note, I also think remarketing is taking a toll on all of us too, i cant tell you how many times i continue to see ads by sites i've visited over and over on my site.
I wish there was a way we could block those ads too.