GigaOm says that IMVU is generating over $1m/mth in revenue:
Flying under the proverbial radar for the last four years, the web-based virtual world chatroom IMVU has released new jaw-breaking data: Since April 2004, it has amassed 20 million registered accounts, with 600,000 of those active monthly users. By comparison, Second Life took five years to acquire about 550,000 active users.
The company, well known to web surfers because of its ubiquitous ads, is now earning $1 million a month in revenue, 90 percent of that from the sale of virtual currency and 10 percent from banner ads embedded in its interface, CEO Cary Rosenzweig said. That works out to about $1.66 a month per active user.
This is within the range of monthlyly ARPU for MMOGs. The article notes that Peak Concureent Uers (PCU) is around 70k, so ARPU based on PCU is >$14/mth.
IMVU sells credits to its users who use these credits to buy items from their catalog to personalize their avatars. The vast majority of the items in the catalog are user generated. Of the 20m registered users, 100k are registered to make items in the catalog, but only a fraction of these are active. Still, they have created 1.7m items, so are averaging 20+ items created per active “item maker”.