Around 80 per cent of revenue from iPhone Apps stems from in-game goods, according to a report by analytics outfit Flurry>.
For the month of September, Flurry found that the average monthly revenue per user in its surveyed Apps was $9 from virtual goods sales, and just over $1 from advertising.
While advertising revenues were roughly the same in September 2009, the estimated average monthly revenue per user from virtual goods has grown from around $1.70 in the space of a year.
Flurry's figures were based on data from a range of 'leading' iOS applications, which it claims sport a combined reach of 2.2 million daily active users.