Valve versus mall shopping is an interesting comparison in that it has shows some strong underlying differences. Anecdotally, most mall shops are clothing, an area where a lot of items contain the same basic function of nudity prevention and weather protection, plus some fashion value of relative merit. Valve's products are more akin to the one or two bookstores in the mall, where the basic function of the product is entertainment where the entertainment value of the product is enhanced by differences between individual products. Similarities do occur within genre, but differentiation is still necessary for success.
Anyway, it's the clothes stores that have neverending sales of their highly interchangable product. I don't think that Waldenbooks would see the same profitability curve as Valve by rotating sales throughout their stock though, as their product requires shelf space and falls within a much smaller price range.
As for L4D's initial price, Valve was smart to set it relatively high, as a multiplayer game like that leverages peer pressure to motivate sales.
Anyway, it's the clothes stores that have neverending sales of their highly interchangable product. I don't think that Waldenbooks would see the same profitability curve as Valve by rotating sales throughout their stock though, as their product requires shelf space and falls within a much smaller price range.
As for L4D's initial price, Valve was smart to set it relatively high, as a multiplayer game like that leverages peer pressure to motivate sales.