Ask HN: Do you earn income from your developer blog?

Many of us probably have fairly similar blogs - code snippets, conference notes, our thoughts on programming, etc.

Are any of you earning income through your developer blog? Not just by finding contract work, or by writing an ebook, but some other method. Maybe selling your libraries, doing training, paid access to "the good stuff".

If you are, can you share what you're doing, how you decided what to do, and how successful it's been?