That seems like a huge price to pay for digg - especially since I assume the way to make money off social news sites is with ads, and the type of community digg attracts is the type that blocks/ignores ads. Maybe I'm way overestimating how many people use that, or maybe that's why they haven't been bought yet?
While Kevin Rose (via Diggnation) and the digg audience generally advocate piracy, that doesn't necessary correlate to the audience using ad blocking software.
Wanting something for free, and wanting something that is already free to be without ads are different things.
You could also serve the ads from the same domain as the thumbnails and images, making it more difficult for blocking software.
Exactly - given that any day some other site could become the top social news site, it seems weird they would be trying to get such a large/unlikely amount.