An amazing stat emerged from Steam's recent sales, that a simple 50% discount to Valve's Left 4 Dead actually made it sell more copies than on launch, a 1600% increase on the previous "no discount" weekend.

Further holiday sales data released show that there's potentially a lot more money to be made from PC games if publishers simply reduce prices. With a 10% discount on offer, sales increase by 35%, and when games are discounted by 75%, the average sales increase was at 1470%.

Doing some simple math and taking a game that retails for $60. Assuming with no discounts, it sells 100,000 copies, bringing in the publisher $6m in revenue. Now if the same game was sold with a 75% discount, or at $15, the 1470% sales increase will means 1.56m copies sold, which at $15, equals $23m! That's almost 4 times as much revenue, thanks largely to converting those that otherwise would have pirated the $60 game into actual payers of a more reasonable $15. This is a simplistic view of what could happen, but Steam's huge success, largely thanks to the numerous sales, suggest that there's some solid numbers backing up the idea that games should be cheaper.

Valve's Gabe Newell also cited a psychologist's report on how to increase the excitement of sale events, which the suggestion that one in 25 buyers should get the game for free.