While Japanese social mobile platforms such as DeNA's Mobage and GREE have been generating plenty of headlines, they're not the only companies building up impressive user numbers.

Indeed, US outfit MocoSpace calls itself "the largest entertainment destination on the mobile internet" - a claim it's backing up with the news it now has 20 million members, who spend 1 million hours online daily.

For the record, GREE claims to have 25 million users, while in February Mobage said its total was 24.5 million users, although it could be argued these services don't run on the mobile internet, but rather are proprietary online platforms.

Games lead the way

MocoSpace is continuing to build out its portal, also announcing the release of four new games - Cage Fighter, In The Club, Goosy Avatar and Goosy Pets - bringing its total to 12.

"The game industry is still focused on apps, but we've proven over the past year that millions of Americans are already playing and buying virtual goods in HTML5 mobile social games," said MocoSpace CTO and co-founder Jamie Hall.

"Thanks to new innovations of our platform, we've made HTML5 game graphics and play as good as the app and playable for anyone with a smartphone, regardless of whether they're using iOS or Android."

Developers interested in working with MocoSpace can apply for funding to make HTML5 content as part of its $1 million Mobile Game Developer Fund. You can contact it via gamescorpATmocospace.com