They don't pick people. They let algorithms that measure search result satisfaction pick from data that people submit. Being a submitter with lots of money doesn't necessarily help you. Being a guy who just wants to plug his own website definitely hurts the odds of your "refinements" ever being selected for widespread use.
Remember, if your "refined" results don't look like any kind of improvement, that "remove" link is right there in front of every user, every time. It's much, much easier to unsubscribe to a publisher than to subscribe in the first place.
True. That's why you don't win by getting a million users to subscribe to you (which you could never do). You win by getting a modest number of subscribers in your niche to subscribe to you, and attracting enough Google attention (or algorithm attention) to say "Hmmm, maybe this guy's topic refinements are worth a test with the general public."
Just like Google every once in a while takes my page 8 listing and puts it on page 1 to test whether it deserves to move up in the ranking, they can auto-detect plausible Co-op "topics" and test them by randomly dropping them in front of the general public (people who didn't subscribe to you, who aren't even necessarily logged into Google). If they measure satisfaction at that point, then they can put that snapshot into the general search results -- and go right on testing, including testing revisions you make to your original "topics".
Exactly. It's a framework for distributing the work of editing a directory. You get a different (and arguably richer) set of tools for presenting your "directory" information to users. You get Google algorithms instead of meta-editors deciding which "editors" are going to have their "work" ever see the light of day (appearing in the main Google search results).
It will be interesting to see if any of the folks who constantly rant about dmoz will invest effort in this. Here's your chance to make your own directory. You just have to do all the work for your niche, sell people on subscribing to it, and then be good enough quality that Google actually someday wants to use it. I suspect many of the folks that get rejection slips from dmoz will likewise be rejected by the Google algorithms associated with Co-op.
That sentiment usually comes from people who don't understand how difficult it is to spam. It has no more potential to mess things up than any of the other hundreds of factors that go into deciding what Google's going to display for any given search query.
All speculation on my part. I have no inside track other than having played with it more than most.