Well, that's an entirely different story right there. There used to be a button similar to Facebook "likes" where the author of an article gets paid with every "like". I forgot the name, but it didn't pan out and died.
Most people like freemium services and sacrifice their privacy for it.
Correct. It's not original functionality. But this is only the beginning of the story. Imagine that you get those non-flat likes (for free) and from others (for your posts), to be able to say "+" for content you like. System collects not just likes, but amount of them. E.x. you like kitties (e.x. 2CRD is your median kitties "likes") and you give more Credits for dog posts (5CRD is your median "like"). And besides that:
dog->bulldog (7CRD median)
and
dog->poodle (0 CRD).
All this info help system to "understand" your interests precisely and help to buld your Interest Matrix. All those transactions stored in the blockchain and open for everyone. But we're a privacy respect service, your transaction can be open, but your profile can be anonymous or you can open your private info (encrypted) only for a few (give them access to the the key to un-encrypt, all in auto mode. Just click one button). That opens the door to the user-centric services: anyone can build his/her services, and we have the same blockchain access like others.
You can sell CRD for WGD, so its have value and you're spending them wisely enough. That helps to avoid spam effectivly. Please find more in the WhitePaper. There's a lot of information.