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.
Worst of all for me, they restrict downloads by IP address so even people with legitimate U.S. credit cards cannot download even their free videos. Actually, they allow you to pay for the product but once you've paid they don't allow you to download. This makes absolutely not sense since you can buy DVDs from Amazon and they are happy to ship them to you anywhere in the world. (iTunes Store has no such restriction - all you need is a legit U.S. credit card, or a gift certificate. For expats like myself, or the world traveler wanting to download the latest episode of her favorite TV show from a hotel room, this is an absolute must.)
A couple of months back I got an invite to do a product evaluation of Unbox, which I did (you got a $5 gift certificate for your trouble, if I remember). I've done many product evaluations in the past, and this is the only one that got me so angry that my blood was boiling. I let them know at every chance how much I thought their product stunk. I don't know if any of that penetrated their conscious, or if they've changed anything about Unbox since I last tried it, but my experience was so bad that unless they try extremely hard to convince me things have changed there is absolutely no way I'm even going near it again. And to anyone who asks I would tell them to stay way away too.