Forum Moderators: skibum
SSI, external js, or even IFRAMES offers a way to design in some central distribution of affiliate code.
On the plus side, you can usually spot this by clicking your affiliate link and checking things out before you promote them.
To add to the list of tricks:
LinkShare merchants adjusting return days after you get comfortable with them. Explained in detail in this thread [webmasterworld.com].
Not only do they milk branding from CPC campaigns, they are now doing so with CPA. Clickthroughs? Some of them don't care - they just want their graphics plastered on your page. Grabbing the mindshare, at the publisher's expense.