Here's a way in which opt-in, almost-everyone-is-allowed web site monetization schemes could skew how people talk about products and web services. When I checked into my Amazon Associates page today, there is a notice saying that I can earn "up to 10% commission" for promoting Amazon Unbox on my site. Since this is 1.5% higher than even the highest tier of regular Amazon commission rates, I'm pretty sure a lot of people will aggressively promote Unbox on their sites now.
I couldn't do this even if they paid me a 100% commission. Unbox is a horrible, horrible product, unlike most of the goods and services that Amazon offers. (Aside from Unbox I'm a very happy long time customer of the Amazon empire.) Its DRM scheme is so terribly restrictive as to be crippling, it's Windows only (and tied to only one machine), and the downloads are, in my experience, extremely slow. And just try uninstalling their mess of a software - it's a huge pain in the ass.