Very interesting, thanks Alvin.
I wonder if they class feeder sites in the same category as doorway pages? The new definition tends to lean towards this. If so, I wonder where they draw the line between what is a feeder site and what is a microsite? For example which side of the fence does the site that is currently number one on google for this
search sit? They are obviously not being penalised by google, even though the site does act as a keyword targeted feeder site to the main ecommerce site (perhaps they have done enough to make their site appear to google to be a normal site rather than a feeder site).