[hakfoo]

At what point does this start to cut down on actual sales volume?

eBay (mentioned in the article) has gotten pretty bad in this way lately. There are plenty of categories where the sponsored listings are a tiny or non-representative subset of the whole.

So if you start browsing by jumping from suggestion to suggestion, you rapidly exhaust the available paid listings. Will customers recognize they aren't seeing everything, then continue to dig and search to find more, or will they decide they're out of luck and leave?

I could imagine tweaking it to a feed where paid listings are n times more likely to be shown, but filling in a few slots from random unadvertised products in the category.