Ad blockers, but mostly an ever growing number of mobile device users are what's "killing" the industry. Throw in the fact that AdSense is now not allowing their ads on sites displaying popups and you've got a real problem.
Don't forget that Chrome will have a built-in ad blocker that blocks pop-unders and other ads not considered "acceptable" by Acceptable Ads. Naturally, Google's text ads are to be considered "acceptable". And then there's the issue of an "anonymous" buyer of one of the biggest ad blockers, which also deems Google's text link ads "acceptable. Just a quick search the other day found some javascript which purports the ability to block visitors using ad blockers. May be worth looking into. It seems that Google and others are trying to drive webmasters to Google's text link ads which I hate.
PopAds is certainly not dead. I will agree that rates are very sad and predictions are not good either, but we still trade nearly 100 million impressions a day.