From what I've observed, the "normal" computer game is expected to have a product life cycle similar to a movie release.
Movie releases peak within 1-3 weeks of initial release and then have a slide of varying slope until they disappear from theaters. Then they peak again (but nowhere near as high) when they are released to video before settling down into a more-or-less stable rental pattern. The final peak they see is when the movie hits Pay Per View.
The bummer of treating computer games this way is that they only have a single peak. Maybe they have some semblance of a peak when the title hits the discount rack, but I expect it's rather anticlimatical.
Referring back to my previous post about traditional board/party games...it takes an average of 4 years for a new product to become "successful". Ironically, most new game companies in that industry are defunct within 2 years.
When I was reading about this I pondered why computer games don't have the longevity of traditional board/party games. I think it's a problem with a couple of facets:
1. Computer game developers have decided that their game simply cannot viably exist for more 3-6 months.
2. Computer games are "technology" driven rather than gameplay driven.
3. Most computer games are one-play-only, just like movies or novels. You might play/see/read it again, but it loses something vital in the repetition, and it becomes less actual entertainment and more of a timekiller.
Reason #1 is essentially an outgrowth of reasons #2 and #3.
The game "Risk" was released in the 1960s. As the "technology" of board games improved, Risk kept up, moving from rough wooden markers to several versions of plastic tokens up to the finely detailed figurines in the current release. Has the game itself changed significantly in that time period? No. There have been some rules refinement, but these were the result of years of gameplay and feedback and had nothing to do with the availability of new types of dice and better-looking plastic tokens.
About the only computer game I can think of that has achieved something similar is Castle Wolfenstein/Doom/Quake. The basic game hasn't changed much at all, but the game display (graphics, sound, interface) has been improved hellaciously.
Anyone else have any thoughts on this?