Doesn't sound like you may necessarily want to expand this funding source, but if you do, I also run a content-heavy site that currently runs on donations. I've been doing it without paying a dime myself over the past 8 years or so.

Some things I've learned:

- Ask for specific dollar amounts. It'll give users an idea of what they should type in. - Make that donation link more prominent on the page. The "this PayPal link" <a> tag is pretty hidden at the bottom. - Offer incentives. I give my donors a trophy for their site account when they give something, and there are certain tiers (e.g. gold trophy for $50, silver for $25, etc.) Requires a bit of management on your side of things, but it could pay off.