The increase — from $1.7 billion in 2009 — is driven primarily through the uptake of video chat and subscription-based services, said Juniper Research's report, which noted that the adult mobile market is only now maturing and beginning to monetize traffic by offering mobile-optimized content and billing mechanisms.
Juniper Research says that video chat service providers report a combination of high retention rates and — with services often billed at several dollars per minutes — of very high average revenue per user.
Meanwhile, the report said, the industry is experiencing a transition from pay-per-download to subscription models as direct-to-consumer adult sites gain traction and traffic by offering a wide range of specialized niche content.
According to the report's author, Dr. Windsor Holden, "In Western Europe, adult areas on operator portals were relatively successful, as were off-portal services billed via premium-rated SMS.
"As people have increasingly surfed the Internet via the mobile, they're discovering a wealth of free content — much of it not optimised for the mobile experience, but still more than sufficient for casual users."