[riscy]

You can cover all of the points you made by loading a Bitcoin wallet and having the plugin deduct fractions of a BTC when you visit these web pages, and when the wallet is empty ads are loaded instead. The main loser in this situation is Google, since the site creators get all of the money. Users may have privacy concerns since BTC transactions are on a public record, but you can keep creating new Bitcoin wallets automatically to mitigate this concern.

[ariwilson]

How much do you pay per visit?

[riscy]

A user's client should respond with an accept/reject response to the price offered by the website. Everything else would be determined freely: Clients can be created with price range configurations as desired (perhaps per website, in a probabilistic way, and/or some cost-concious settings), and website owners can analyze their visitor's accept/reject rates to determine how much to ask for before falling back on ads.

[marak830]

Honest question, how much does an ad cost per 1000 impression(i think thats how its costed?).

I would imagine its that cost.

That is how much their being paid by the advertisers to keep the information open(as opposed via a paywall).

Im not sure how everyone else sees it, but thats my impression.