Nintendo's Wii is dominating the current generation of video-game console sales, but in targeting the broader consumer market, it looks like the company has ended up with a decidedly casual level of engagement. A new Nielsen report puts the Wii behind Sony's PlayStation 2 and 3 and both of Microsoft's Xbox machines in the amount of time people spend using the consoles.

The accompanying chart, from the Nielsen report, shows average usage patterns for December 2008, based on a Nielsen sample. The company defines the "active user percentage" as "how often a person used their console out of the total amount of time the console could have been used during the measurement period." Read the full report here: PDF, 9 pages.

In a lot of ways, the numbers make sense. By definition, many of the people fueling sales of the Wii are not hard-core gamers. But the usage trends are notable in that console makers and game developers count heavily on follow-up sales of games, accessories and online downloads in the months and years after purchase.

"The Wii and its predecessor, the GameCube, have  "the smallest numbers in terms of daily average number of sessions, average usage
days, and active user percent," Nielsen says in the report. "Predominant users of the Wii and GameCube are likely to use these consoles at most once a week and for fewer minutes and the fewest number of sessions compared to the other two groups of consoles."