Every now and then my earnings literally cut in half for a day or two, and I get the feeling it's a shitty ad that got into the network and is taking up all my clicks because my clicks/impressions/traffic stay the same but my earnings/ecpm cut in half. Is there anyway to spot these ads based on their url, title, etc. so I can filter out these spammy sites? I'm getting sick of getting screwed out of money every now and then.
let adsense do its job and focus on yours. There's no way to spot them, and anyway you don't want to spend your time on that, spend it on increasing your traffic or improving your ctr.
I don't actually suggest that you do this, but because Google already prioritises high-paying ads, not because it can't be done. You think G wants low-paying ads on your site or any other displaying AdSense? Nope. But if you insist ... when I was still active with AdSense it was fairly easy to dig up which ads were paying crap by using a third-party analytics software on the page, and URL channels in AdSense. You can root them out that way then filter specific sites using the Competitive Ad Filter in AdSense, if it still has that feature (again, it's been some time since I used AdSense so my advice may be a bit out of date; an ironic Google search of what I'm describing above will probably yield current info on the technique.) Frank
I've used Statcounter to eliminate low-paying ads. But it's better to eliminate advertisers you see that aren't relevant to your users.