In its first-ever quarterly online game subscription tracking report - covering October 2007 to March 2008 - the NPD Group has gathered data claiming that online subscriptions, including MMO, casual, and console titles, represent over $1 billion annually to the U.S. gaming industry.

The NPD Group calculated these results by taking the monthly averages it had estimated from a newly compiled gamer panel for Q4 2007 and Q1 2008, respectively $94.3 million and $80.1 million, and multiplying the average of those two by 12 to get the annualized equivalent.

Said NPD spokeswoman Anita Frazier: "Now that NPD can estimate the value of the subscription market, it's clear that there is a sizable chunk of revenue being generated by PC gaming beyond what is reflected in retail sales."

The online subscriptions tracking report went on to show claims that 11 million North American gamers hold monthly subscriptions to online games. According to the report, revenues from console subscriptions rose 9% on an average monthly basis since Q4 2007 to Q1 2008.

The NPD Group also listed its own estimates of the top 5 rankings for MMOs and gaming subscription (largely casual) websites during the Q4 2007 to Q1 2008 period.

MMO/PC Game Subscribers:

1. World of Warcraft
2. RuneScape
3. Lord of the Rings Online
4. Final Fantasy XI
5. City of Heroes

Gaming Website Subscribers:

1. Pogo.com
2. Realarcade.com
3. Bigfishgames.com
4. Gametap.com
5. Disney.com

Said Frazier: "By contrasting the demographics of MMO players against those of gaming website players, the broad appeal of PC gaming is clearly evident. While the majority of gaming website players are females over the age of 35, MMOG players are largely males under the age of 35. The variety of content available to play games on the PC clearly can draw a diverse audience."

[The preceding article originally ran at Worlds in Motion sister site Gamasutra.]