I'd change all amazon links to affiliate links (assuming they weren't affiliate links already, not that I've seen very many here). There are a boat load of posts devoted to books here, and lots of book recommendations going on outside those posts. The big book threads get linked to again and again.
The only other thing I can suggest that I think would appeal to the community would be to sell ads to ycombinator startups at ridiculously low rates. One to two ads per page, nothing obscene.
The problem with that would be that it would encourage spam. I would only have affiliate links in quality filtered lists (Top Picks/Most Recommended, Editors Choice, and personal lists that users could maintain on their profile page).
Advertising inherently seems to warp content, I think a premium membership option would put the incentive on satisfying user interests, rather than marketers.
It would only encourage PG to spam. :p (I think the idea behind this is that the site converts them to PG's amazon affiliate account, so he's making the referral bonuses.)
I was going to mention that, but I don't think it would mesh with HN that well. First, it would change everything to an affiliate link, not just amazon. More importantly, it doesn't seem to work with links you open in a new tab because it uses a lot of JS redirects (also, something people on HN may not find very attractive).
You definitely can. On average, you make around 6% on ANYTHING someone who clicks through puts in their shopping cart that session.
A friend of mine linked to a downloadable part of the tron soundtrack (a dollar or so a song). Someone bought the Adobe Creative Suite. My friend made $300 that day.
On a less "blind luck" side of the fence... if you have a blog with a few thousand hits per month, and you can just reference a product on Amazon on a few posts that month, you can get a pretty solid number of people clicking through.
The only other thing I can suggest that I think would appeal to the community would be to sell ads to ycombinator startups at ridiculously low rates. One to two ads per page, nothing obscene.