jimbeetle - 3:57 pm on Nov 22, 2010 (gmt 0)

why are affiliate sites being blocked from Adsense

You basically answered this yourself in your original post:

G sees them as containing bridge pages which exist just to send the visitor to another site

If that's the affiliate's entire strategy -- "Click here to buy" -- then Google doesn't want that, never really did. The value add is the most important strategy to be able to survive as an affiliate these days, has been for a number of years.

Just as an aside, there's one thing you have to keep in mind about this:

Google, with their purchase of boutiques.com is now, itself, an affiliate.

Google actually introduced the commission model for some Products advertisers last year, so the somewhat affiliate-looking aspect of this is actually old news. I might be right, though most probably wrong, but I'm looking at boutiques as a model for a new Google Products on steroids.