I'm willing to bet that would work out to FAR less than $25.

That would be the best system. 95% of all revenue generated through use of the data, with transparent accounting of every use of the data. Some of that can be hard to quantify, but Google has already run these numbers. They wouldn't float a program like this if they didn't already know that a persons browsing history for a year can be used by them to bring in several thousand times more revenue than it will cost.

(As to how I got 95%.. I figured 10% is the centuries-old standard "finder's fee" people collect when they hook up a buyer and a seller. Google isn't even doing this. They're doing more the equivalent of 'let us harvest all the wheat from your field, and we'll go sell it'. Google can't grow the wheat, so they have to buy it from someone else. You could sell it directly, but it would be a minor pain in the ass. So they're likely entitled to about half of the standard finder's fee.)

Well that raises another interesting question, what is the worst? Is it selling it? Is it publishing your browsing history with your name on a blog?

That was my first thought too, and allowing it be revokable by either party.