I think the page refreshes automatically... I was keeping an eye on it pretty closely last night (because of the companions stretch goal) and it seemed to increase by about $1000 every few minutes.
I guess the increase is due to the recent number of gameplay videos with Youtube-channel people, like TotalBiscuit and Angry Joe.
It's just been announced that Divinity hit the 800k milestone to add Companions. This is something I'm really excited about, Divinity is looking awesome but Companions is a feature I would have sorely missed.
Now they're in I'd just like to say Yay!
Me, too. I was really worried they weren't going to meet that goal.
Now I'm just concerned that, with all of these stretch goals met, Larian will need a lot more time to finish the game. A 2013 release seems too much to hope for.