Ask HN: Any advice on how to promote an API?

Hello all,

please share your experience and advice on how to market an API to developers and software vendors.

Do you use 3scale.net?

Until now I had to drag nearly every user by hand into my service[0], so I was wondering how other people do it. I'm experimenting a bit with google-adwords, but since this is only a side project for me, my budget is low and limited.

Please share your API project together with some insights on how you got developers to notice.

[0] http://template2pdf.com/