I see posts like this regularly on HN (lists of stuff you should do to hire that top 1% of talent). What I don't recall seeing, though, is a post more along the lines of employment branding. I understand how for very small start-ups that may just be a waste of time but when you get to a certain point it seems like you're going to want to do something. That might just be having a labs.yourCompany.com blog, or releasing an open-source project once in a while. I think that great devs want to work places where they know the work is interesting/fun/whatever. It's a lot easier for you to get the word out via say a blog, rather than have a 1-1 conversation with someone over the phone to communicate the cool stuff you're doing. Just my 2 cents.