If you were anywhere near a video game retailer over the past couple days you would have noted that not only was the new Call of Duty game available but also that many people were lining up day and night to secure themselves a copy of the latest release of the now annual series.

Today, the game’s publisher Activision has noted that on day one alone the company had sold 6.5 million copies of the game, in the US and UK markets, for the various consoles it was released for including PS3, 360 and PC to name a few. While EA’s Battlefield 3 has certainly closed the gap on the leader in modern-day war games, what with BF3 shipping 5 million units in the first week, it’s clear that they have a lot of work to do if they ever hope to surpass the completely unexplainable success that COD now has.

This leads to an interesting question: how long can Activision keep pumping out this title each year and seeing increased sales? Eventually, the bubble has to burst. Look at the Guitar Hero games for example, which is another series published by Activision. The rhythm game series enjoyed success over the years selling over 25 million copies of the various titles but has since decreased exponentially due to the high volume of games being released (There were seven Hero titles released in 2010).

Could Call of Duty share the same fate? Looking at the numbers released today, it’s hard to see that happen but I wouldn’t say it’s impossible.

During a conference call on Wednesday, Activision CEO Robert Kotick also confirmed that a new Call of Duty is in the works and will be released, as usual, in November of next year.

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