Pay-to-play hurts consumers a lot because the search results are tainted by it, and it hurts adoption because google is double dipping with it's own CPC customers.
For the user, it's the difference between: 1) having a wasteland of outdated, incomplete and inaccurate information or 2) having a browsable set of ads.
In the latter case, you're aware there's money behind the placement, but it's still far more useful than Google trying their best to do organic search over a corpus that's complete crap.
I came to ask whether it is likely Google will be improving their product search? As someone who remembers all the way back to Froogle, I still find myself on product search, obsessively checking amazon, google, ali express, ebay, etc. to try to find the best prices and to find competing products.
Most often, that leads me to Asia. [Yes, I'm a geek, so most days I'm looking for consumer electronics.] I don't know but that Google is just as concerned with Alibaba's recent IPO, and Amazon is just a convenient whipping boy.
As a side note, no, I still don't really take ebay listings seriously. Ebay and Paypal are still so seller-hostile that I just use them for research and then try to buy somewhere else.
The problem with the Chinese goods is that it's very hard to locate high quality goods. The review systems are useless(full of junk) , and there's little reliable data about quality in english. So amazon becomes the default.