Sure - that's probably worth another blog post too. We used a combination of twitter, adwords, marketing forums, and personal network.
Also - could/would people click on more than one button once they found out they were non-functional? It could be that some features would be best developed in tandem with others.
Repeat clicks are definitely interesting. It makes sense that once a button was clicked and found to be non-functional, that may prevent future interaction. But that first click still holds value. It'd be interesting to pull stats on how many unique visitors generated those click events.