New research from Flirtomatic, provider of a mobile and web-based messaging service available in the UK and Germany, suggests viral marketing via mobile phones has plenty of room to grow. A majority of the 5,800 Flirtomatic users who responded to the survey said they primarily use their mobile phones, not the web, to access the service. And nearly 84 percent of those surveyed said they use their phones as their primary Internet connection at home. More importantly, some 38 percent have invited a friend to join Flirtomatic, and only 5 percent said they wouldn’t pass along invitations to others.

While this data only pertains to Flirtomatic, it is proof that the right kind of service can tap into the viral marketing gold mine on mobile phones. While Flirtomatic has no plans to include advertising in messages, Mark Curtis, CEO of Handmade Mobile, the company behind Flirtomatic, said other mobile messaging companies could take advantage of the opportunity suggested by the company’s research.

Mary Meeker, who leads Morgan Stanley’s global technology research, just spoke at the Web 2.0 Summit, where she pointed out that ads are ultimately going to follow eyeballs. Meeker said the growth of Opera’s mobile web browser — which CEO Jon S. von Tetzchner told us is quite healthy — illustrates mobile growth overall. Taken together with Flirtomatic’s survey data, the future of mobile advertising looks very bright indeed.