[oziumjinx]

Here's a revenue model: Offer users with certain karma levels discounts from startups that provide services. The more karma you have, the higher discount you may be able to receive from a variety of startups/services. When a user cashes in their karma for the service, HN gets a recurring affiliate fee based on the total fees paid to said startup. And of course users with lower karma can still get some kind of discount from the services. Once those users karma reaches a new higher level, another discount kicks in.

To personalize this a bit, show a simple survey link on the main nav bar that lets users select the types of services they are intereted in. This would then be used to populate a sidebar with dinky ads or other promotions from startups/events.

Here's another one: Have events/conferences sponsor specific threads in HN...Whichever comment receives the most points get a discount or free pass. Once again, affiliate fees on other users signing up for the event kicks back to HN.

And another: create an automated newsletter that sends you a roundup of the days highest voted stories (with topic personlization if you want [ie, only send me Ask HN or 'seeking feedback' type stories]). Sell a few ads in the sidebar to startups on a budget.

If HN is averaging 60k uniques/day, that newsletter could grow pretty quickly. Sell of small banners at a decent CPM and it should make some money. And then of course layer on a taxonomy binding ad server that shows ads relevant to the topic(s) that are displayed in the newsletter based on the users preferences.