Salesforce.com on Thursday announced the acquisition of Dimdim in a $31 million cash deal aimed at boosting the real-time communications technologies behind the CRM vendor's Chatter service.

Founded in 2007, Dimdim provides a Web-conferencing and collaboration service. Salesforce said it will integrate Dimdim's presence-awareness, messaging and screen-sharing technologies with Chatter to advance what the company calls its most successful product launch to date.

"More than 60,000 of our 87,200 customers have deployed Chatter since its release in June," said George Hu, executive vice president, platform and marketing, in a conference call with analysts. "Customers that have deployed Chatter within our Sales Cloud and Service Cloud have shown higher login rates and higher usage rates."

Dimdim's technologies will make the Salesforce collaboration experience even stickier, Hu said. He noted that Facebook has shown the appeal of blended collaboration and communications capabilities on its popular social networking site.

Salesforce stressed that it not just buying Dimdim's technology; it will also retain the company's engineering team, which is focused on cloud-based communication and collaboration. Dimdim is based in Lowell, Mass., but many of its 75 employees are developers based in India.

Salesforce will not continue Dimdim's stand-alone Web conferencing business. Rather, it will focus the engineering team on integrating Dimdim's technology with Chatter as quickly as possible.

Saleforce.com earlier this week completed its previously announced $212 million cash acquisition of Heroku, a fast-growing cloud application platform for writing Ruby-based applications. The Heroku and Dimdim acquisitions are both aimed at bolstering Salesforce.com's technology and long-term growth rather than short-term earnings. As such, the deals will dilute Saleforce.com earnings per share by three cents in the fourth quarter of fiscal year 2011 (ending January 31, 2011) and by 16 to 18 cents in fiscal year 2012.