I'm so happy for these guys. Selling 300,000 copies @ $30 each is life-changing money. Over the years they've accepted donations but from what I've seen it's tended to a few thousand dollars a month. Decent but not a lot for 2 people.
I still find DF really inaccessible but this Steam release will prompt me to give it another go. Whatever the case, I'm happy for their success.