TradeDoubler is the big European affiliate site. It's aimed at the high end of the market and does not aggressively recruit affiliates though it certainly goes after merchants.
Today TradeDoubler launched a number of "Free content" initiatives. Webmasters can simply cut'n'paste pre-written text provided by TradeDoubler and the merchant into their own site. This goes beyond adding a banner or a content unit but to actual content. Whereas this is aimed at PPC users - free landing pages, essentially, - it'll not have a good natural SEO effect. It's a good way to get into trouble for duplicate content. If you're paranoid you'll worry about Matt's post about "Math SOS"
who put live entirely off topic pages and sold links from them. It's important to note that that's not the same as creating a content page and putting affiliate links off from it. Previously Matt had said that sites which sold links would loose their ability to pass PageRank on, this is clearly something different.
And yes, the sly will notice that I link to TradeDoubler with my own affiliate link. Heh. Scrubbing up an extra £2? Nooo. (I'll claim) Just giving an example of a valid affiliate link.