incrediBILL - 10:26 pm on Apr 1, 2012 (gmt 0)
They tried that and there was a huge outcry.
They certainly didn't pay attention to the huge outcry on meta tags for opt-out vs. a trivial robots.txt implementation. They must be picking and choosing who is OK to tick off and who isn't as webmasters obviously don't rate.
Many businesses have went broke paying attention to the huge outcry. People flipped out over ads in YouTube yet they persist. Outcries don't pay the wages, servers or bandwidth fees but affiliate IDs do.
Besides, if it were done silently, in a server-side redirect, the end users would never be the wiser about the affiliate IDs.
The mistake was making them visible where people can see them.