First-party Nintendo software accounted for 47 per cent of Wii revenue in the US during 2009, and 38 per cent of all units sold at retail.
That's according to NPD data quoted by analyst Michael Pachter on forum Neogaf, revealing that 27.5 million first-party games were sold totalling $1.53 billion in sales, out of the overall 72.4 million units and $3.23 billion in Wii game sales during the year.
The average third-party game on Wii sold for $37.85, while the average first-party title from Nintendo sold for $55.63.
Pachter also pointed out that Capcom's Resident Evil: The Darkside Chronicles and EA's Dead Space: Extraction were were outside of the top 150 best-selling games on Wii, at 151 and 261 respectively. Earlier this month, Capcom in France expressed disappointment at sales of its mature Wii game.
The highest ranking Guitar Hero game for Wii was Guitar Hero: World Tour at number 30, which was outsold by Just Dance, Cabela's Big Game Hunter, Deal or No Deal and The Biggest Loser.
"The conclusion I draw from this is that the Wii audience is far more casual and harder to reach than the PS3 or 360 audiences, and they buy brand name software (with 'Wii' or 'Mario' in the title, or with a TV/product tie-in)," wrote Pachter.
"The average selling price of third-party titles says a lot, coming in almost $7 below the average for all Wii titles, and almost $18 below first party titles."