Digital Chocolate announced a “a multi-million dollar revolving line of credit” this week, from Silicon-Valley based Bridge Bank, “for general corporate purposes.” The money will, we assume, specifically go towards projects related to its latest efforts in social and mobile gaming.

The company has been around since 2003, and raised $43.9 million in three rounds, the most recent of which was in 2006; it has developed more than 80 titles that span from web, to mobile, to social games. Founder Trip Hawkins has previously told us that it has been profitable for a couple years already, partly through syndicating its games. While it didn’t disclose funding details, this line of credit is likely a cheaper way for it to finance small acquisitions, large ad campaigns, or other unusual expenditures, instead of raising more venture money.

And, while Digital Chocolate wasn’t specific about its plans, the company has been focusing on mobile and social gaming recently, so we expect it to spend the credit in those areas — if it hasn’t started already. Having launched the “NanoVerse” concept this spring — a universe of characters and virtual goods that span its titles — it has continued to expand, most recently with new social title Millionaire City. It’s a city-building Facebook game that expands on its earlier MyTown version of the genre, and it has been doing well in the couple weeks it’s been out, having racked up 282,000 monthly active users and 72,100 daily active users. Digital Chocolate is seeing growth from other games, too, according to our independent AppData service, and it is now at 2.35 million MAU and 260,000 DAU overall. And the company isn’t just focused on social, as it has also just released a new version of its Rollercoaster Rush game for Blackberry devices.

Especially given that it got started on Facebook years after many competitors, Digital Chocolate is one to watch. On a final note, there seems to be a management shift happening at the company as well, as president Ilkka Paananen recently stepped down to spend more time with his family, according to an email obtained by casualgaming.biz.