Huge Left 4 Dead sales spike after Steam discount

The Left 4 Dead 50% sale causes the game to sell more than its launch weekend.

During a DICE keynote, Valve's co-founder Gabe Newell announced the staggering results of their 50% Left 4 Dead sale on their online distributing service Steam.

The game sold around 30% more last weekend than it did during its launch and a staggering 3,000% more than it did only two weeks ago. (NB: The results only factor in online Steam purchases.)

Newell factors the steep increase to the combination of not only the 50% sale, but the newly announced add-on content, and limited free trials. The increase in sales far exceeded the company's expectations.

Valve also released statistics for the whole of Steam, where new customers jumped 1600% over the same weekend. The Steam holiday discounts resulted in the following increases in sales:

10% price reduction = 35% increase in sales

25% price reduction = 245% increase in sales

50% price reduction = 320% increase in sales

75% price reduction = 1470% increase in sales

At 75% off Valve made 15% more money than they were at full price, proving that well timed sales really do work.

Moreover, Shacknews.com reports that Valve has now hired an experimental psychologist to develop new ideas to increase excitement and sales for a title. One suggestion was to provide a free copy to every 25th buyer of a game.