This is a little lesson for those of you who want to do analysis on sales numbers.
What is the best-selling Atari 2600 game ever? Pac-Man, weighing in at a very impressive 7 million copies sold (unprecedented for the time; the attach rate of Pac-Man was well over 50% during its peak). It also moved an impressive number of systems, resulting in one of the best years for the Atari 2600 in 1982. At a glance, this game is the very image of a killer app. And it was, in a more literal sense than we usually intend with that term: Pac-Man for the Atari 2600 helped set off the collapse of the video game industry.
Pac-Man is a prime example of a game falling victim to what we so lovingly know as "backlash". The game was a huge seller when it came out, and everyone wanted a copy. Then word got around that the port was of very poor quality, and sales numbers dropped through the floor. Worse still for Atari and their merchants, copies were being returned like crazy, especially to Sears (collectors have noticed that Sears-branded copies of Pac-Man 2600 are the rarest type, yet Sears was the most popular Atari 2600 reseller at the time). The game was so over-produced as well that 5 million unsold copies were left over when Atari finally pulled the plug on the 2600 (and that doesn't even account for returned copies, either).
This is why you should never rejoice when a game sells millions of copies right out the door, yet vanishes from the charts within a few months of release. As Pac-Man 2600 demonstrated so long ago, this can prove to be a very bad sign. And since there is no way to track copies that are returned, resold or destroyed, we have even less ability to make an effective measure of how well games really do.
If you haven't sussed it out yet, the lesson here is this: never trust sales numbers to give you the whole picture. There is a lot more going on than raw numbers, and even what looks to be a record-setting blockbuster on paper can turn out to be a massive failure or system killer in reality.
Sky Render - Sanity is for the weak.