DiscoJer
Member
and Digtal Sales is Booming for the Vita
SOURCE
The original source seems to be
http://www.destructoid.com/sony-digital-business-is-the-faster-growing-business--246237.phtml
I figure you could make a vague estimate by simply comparing the number of ratings that a PS3 game has versus a Vita game, if they happen to be released in the same time frame.
Like looking at the Web Store, Assassin's Creed 3 has 2913 ratings, while Assassin's Creed Vita has 1681 ratings.
Need for Speed: Most Wanted is pretty close: 1295 PS3, 1112 Vita.