Of the nearly 19,000 gamers questioned--some as young as 2 years old--the survey found that those classified as "Extreme Gamers" played an average of just over two full days per week, or 48.5 hours. It's a fairly dramatic number, considering that (as a whole) U.S. gamers spend an average of thirteen hours per week playing games.

Depending on their gaming habits, study participants were sorted into one of seven groups: Extreme Gamers, Avid PC Gamers, Heavy Portable Gamers, Console Gamers, Online PC Gamers, Offline PC Gamers, and Secondary Gamers.

Overall, hours spent gaming on PC and consoles have respectively increased six and nine percent over last year, though an exact breakdown was not provided. Handheld gaming, on the other hand, took a sixteen percent dive since last year.

The audience is also getting a bit older--the study found that gamers are now thirty-two years old on average, up from last year's thirty-one. The study surmises that "Avid PC Gamers" and "Offline PC Gamers" comprise the eldest segments of the gaming populace at a combined nineteen percent of overall gamers with an average age of forty-two years. The "Avid PC Gamer" segment is also the most heavily supportive of digital distribution, purchasing thirty percent of their games digitally in the past three months.

The report also notes that overall game sales made through digital distribution continue to rise, as seventeen percent of games were purchased digitally--up from sixteen percent last year. A per-platform breakdown of that figure was not provided, though the past year has seen PCs, consoles and handhelds further embrace digital downloads.

If you're curious about how NPD gathered its data, the methodology employed for the recent NPD survey is as follows:

In January 2010, The NPD Group fielded an online survey that was completed by 18,872 consumer panel members ages 2 and older. Responses for individuals ages 13 and older were captured directly, and responses for individuals ages 2-12 were captured by "surrogate reporting," whereby a parent/guardian brings the child to the computer to answer questions, and the child then answers either with or without the guardian's assistance. Final survey data was weighted and balanced to represent the U.S. population of individuals ages 2 and older.