Ask HN: Should I open up my apps data so anyone can use and derive from it?

I've built a site for climbers called Bouldr (http://bouldr.net) - a worldwide, user editable guidebook for climbers.

Recently, I've been toying with the idea of making all of the data that has been submitted to Bouldr open (Creative-Commons) to everyone in the form of a downloadable archive as well as an API.

My thinking is that if I make the data available in a similar way to how Stack Overflow already does, then more climbers will be motivated to contribute, and more interesting uses of the data will come to light.

My only concern is that I may inadvertently kill my site to death by overlooking some glaring reason that this is a bad idea.

So my question is: Is opening up the data from Bouldr a good / bad / stupid / dangerous idea, and why?

Cheers!