There could be as many as 35 million paying subscribers to mobile adult websites by 2015, according to Juniper Research.
The analyst claims that the boom in smartphone sales, as well as cheap data tariffs, has led to more consumers visiting mobile adult sites, and then handing over their credit card details.
"The opportunity offered by mobile couldn’t be more timely, given that sales from DVDs have collapsed while online paysites have also lost customers and revenues as a result of the proliferation of tube sites," says Juniper’s Dr Windsor Holden.
Juniper warns that casual users may find more adult content for free in future, meaning that the adult content firms should focus instead on "high-value niche content", and customer retention.
Juniper has published a Mobile Adult white paper outlining some of its findings, as well as a video, which can be viewed at Mobile Entertainment.