Have you tried mailing lists? Surely you're already subscribed to several industry-specific mailing lists or groups. Add "We're hiring!" and a link to your sig

Have you tried mailing lists? Surely you're already subscribed to several industry-specific mailing lists or groups. Add "We're hiring!" and a link to your signature whenever you post. A trick that helped me some time ago was going to a local bookstore and sticking a "we're hiring: come and have a coffee with us" post-it inside of some relevant technical books. Try it: it works :-)