How are you going to do this? If you put ebay.com or ebay.co.uk in the filter you block them from ALL of your pages on all of your sites.

Besides, what is actually happening is that Ebay affilliates are blocking ad placement on your site of (possibly) genuine advertisers wanting to sell products to your visitors in favour of the typical "New and used dead cat's - get 'em whilst still warm" junk.

Just block ebay - period.

Actually, blocking EBAY.COM is useless for me. Ebay shows up using different URLs. CJ's URLs, for example, using CJ's ugly domain names made entirely with random letters, but I was trying to figure out if Ebay could be fine for some domains and bad for others. I know that a lot of publishers have several domains on the same AdSense account, but I think it makes sense to understand if Ebay is bad for everybody or not. There are some adsensers that read tips and apply them without any further intervention. Would the tip "remove Ebay (if you are able to figure out how it appears on your ads) period" be ok?

As a side question, if I were Ebay, I would have searched for a way to avoid being blocked by the standard "ebay.com" line in competitive ads. Advertising through CJ or any other ad network would allow me to show up, being hidden behind the ad network's URL. The ad network might risk to be blocked, through a cascading effect, but Ebay might pay the network to balance this effect. Is there something I missed and did I write silly things, or is this something you experienced and/or thought too?

As a side question, if I were Ebay, I would have searched for a way to avoid being blocked by the standard "ebay.com" line in competitive ads. Advertising through CJ or any other ad network would allow me to show up, being hidden behind the ad network's URL. The ad network might risk to be blocked, through a cascading effect, but Ebay might pay the network to balance this effect. Is there something I missed and did I write silly things, or is this something you experienced and/or thought too?

More often than not I've found eBay ads to have some ad network's URL rather than an actual ebay URL. In order to get rid of them from my sites I had to find all the variations. Too bad if that might have taken some other advertisers out with them, I simply do not want any ebay ads to appear on my sites.

Icedowl, while having ads through ad networks makes me think that those ads must be low paying ones (because I have to share earnings with one more player), I'm afraid that Ebay (and other advertisers) might obfuscate themselves this way. What if all AdSense advertisers use ad networks? We would have cut a huge slice of earnings. While this is unlikely to happen in the short time, I think this is a weakness in the system. And every weakness is likely to be exploited, sooner or later.