In his new role, Richards will work with the creative, planning and sales teams in devising propositions for clients wanting to use the company's virtual world, avatar and user-generated technology.
Richards began his career client-side with HSBC before moving on to sales promotion agency IMC.
In 1998, he co-founded award-winning London agency, Swordfish, working with clients including BBC, Channel 4, first direct, Reckitt Benckiser, Sony and Warner Bros. Yomego clients include MTV, CSC Media, and Viacom.
Richards said: "Yomego's innovative approach to digital interaction is unique. Virtual world, avatar and AI technology are now being used by forward-thinking clients like MTV to engage and amuse consumers seamlessly across TV, online and mobile platforms.
"The social media landscape is changing fast and this new role gives me the opportunity to work with brands to design this landscape and devise new and exciting levels of interaction."
Mike Antliff, chief executive of Yomego, said: "Steve brings with him extensive agency and client servicing experience and will help us to further define our offering to customers allowing them to reach, engage and inspire their audiences through all social media platforms."