I think we need this too, but I'm skeptical it would work. I'm afraid most of us don't know/trust enough people. For example, I'm considering buying a sofa from store X, but no one I know has ever bought from store X.

There's a good chance that the items you're most ignorant about are also the items your friends are most ignorant about (or at least enough of them that it'll significantly reduce the quantity of the feedback).

Also, once this became a thing, once it became monetizable, my web of trust would shrink drastically. I mean, geez, I'm even suspicious of my doctors prescriptions.

Maybe we need professional reviewers with a transparent system in place to protect against manipulation (as much as possible). Something like Consumer Reports on a larger scale.