A leader in monetization, distribution and publishing services for social and mobile applications, Tapjoy Inc. today announced a funding of $21 million in a round led by Rho Ventures, and participated by existing investors InterWest Partners, North Bridge Ventures and D.E Shaw Ventures.

The company’s recent funding will be used to expand presence across emerging domestic and international application ecosystems, as well as further its stronghold as a leader in distribution and monetization of applications on the iOS, Android, and Facebook platforms. Application media licensing and incubation opportunities will also get a chunk of the fund. All in all, the company has garnered an accumulated fund of $40 million.

“This is a very exciting time to be an application developer, with opportunities that span across platforms and regions. We are thrilled to support application entrepreneurs with our industry leading infrastructure, monetization and distribution IP and services,” said Mihir Shah, president and CEO of Tapjoy.

“We also look forward to continuing our strong and dedicated working relationships with Apple, Facebook, Google, Yahoo and the other social and mobile platforms we invest in and support.”

Tapjoy’s distribution services include the cross-platform viral notification channel Social K-Factor (formally called SocialKast), the cross-app promotion bar AppStrip, and the industry’s most powerful and cost-effective Pay-Per-Install advertising network. The company has been consistent in the deplyoment of product lines which includes new alternative payment solutions for social developers, as well as a virtual goods storefront for mobile developers.

“Tapjoy is a leader in mobile advertising solutions and will continue to be a key strategic partner for Glu as we expand our portfolio of freemium, social mobile games,” said Niccolo de Masi, president and CEO of Glu Mobile, a leading global publisher of games for smartphone and tablet devices. “Their understanding of market dynamics, best practices in mobile advertising, and timely management of promotional campaigns make them a valued partner in the mobile gaming space.”

There are over 5,000 app developers and advertisers that partnered with Tapjoy application monetization and distribution such as GameDuell, Tapulous, Glu, Pinger, Playdom, Kayak, Barnes & Noble, MTV, Bing, Fandango, Groupon, and Intuit.