The release of Activision and Infinity Ward's Call of Duty: Modern Warfare 2 spurred Xbox Live to a record-breaking 2 million concurrent players -- but the attention-grabbing launch plummeted sales of Xbox Live Arcade games, along the way.

Gamasutra sister website GamerBytes' editor Ryan Langley regularly analyzes Xbox Live Arcade Leaderboard data to help determine how well a game may be selling, and his latest look reveals sales for top-selling XBLA games down significantly.

For example, the additional weekly entries on Trials HD's Leaderboards, which have grown by around 15,000 each week for some weeks, dropped 40 percent to about 9,000, while South Park, Zombie Apocalypse and Tower Bloxx Deluxe all saw falls of nearly 50 percent in their increments.

The relative decline for The Behemoth's long-term success Castle Crashers was slightly more modest, slipping from 8,727 to 6,023, although Shadow Complex and TMNT Re-Shelled were close to halved.

Defense Grid saw one of the most dramatic 'extra Leaderboard entries' declines following Modern Warfare 2's launch, from 2010 to just 936.

Gamasutra commenters have also pointed out that Xbox Live's console bannings occurred alongside MW2's launch, and may have contributed to the drop. (However, only about 1 million at maximum of the 20 million Xbox Live userbase were affected.)

The following chart illustrates the significantly slower growth the top Xbox Live Arcade titles' leaderboards have seen around the November 10th release of the market-dominating Modern Warfare 2:



GamerBytes will be analyzing the weekly leaderboards immediately following Modern Warfare 2's release, too, but Langley definitely believes that XBLA Leaderboard additions (and therefore sales) will rebound again.