I asked.  Here's Delphy's advice on supporting a site financially.
- Don't rely on one method.  He recommens Adsense, a Paypal donation button, and Amazon store.
- Don't expect much from Amazon.  It starts at 2-4%, goes up with more sales.  MTS gets about 6%, but that's still only about a "tenner a month", according to Delphy.  So don't rely on Amazon.
- Have a PayPal button, but don't pimp the hell out of it, that annoys people.
- If you can get about 5 people donating monthly, regularly, that usually pays for standard web hosting
- Have a donation meter.  Meters encourage people to donate, and they like to see them.
So now if someone asks, I have something more to say than "Erm, I don't know". 

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HP had this very helpful suggestion.
- Offer pictures of your naked ass for money.
And I would add this.
- Threaten to post pictures of your ugly ass if you don't get money.