That's pretty amazing. I wonder what happens to revenue in the weeks following the sale; do sales dry up completely, or do they stay strong as players recruit their friends, perhaps?
I'm not so sure. People who were considering a purchase probably got it during the sale. Now that the sale has established that the game is "worth" $25, perhaps people will wait longer before buying to see if the price drops again. This may hurt their higher-price sales, not only on this game but on all Steam games.
(At least, that's the logic I'd use. I've bought several games on Steam -- including this one -- all on 10%-75% sales.)
Ah but are you buying because the price is $25 or because it's half the price of $50?
I buy all my games when they go below $30, so it makes no difference to me if the game goes on sale or simply drops in price because I'll grab it anyway. Most times I'll grab the game used as I get a disc in excellent quality, usually $10 cheaper than the original game. I'm already watching the used Fable 2 and Fallout 3 games for when they hit $30 because I'm snatching them up.
Edit: I'm an exceptional bastard when it comes to used games, because I always look through them because there's often a wrongly priced copy that they have to honor the pricing on. I got Bully: SE $10 cheaper and just a few days ago Mass Effect $8 cheaper because of the mistake. I was actually waiting before getting Mass Effect as I wanted to complete Bully, but when I saw a huge stack saying $33 and then in the bottom row one saying $25 I couldn't resist, especially considering Mass Effect used prices are going to start going up through this year with ME 2 coming out in the spring of 2010.