Carbonite, a Boston company, that provides a way to back up your PC over the Internet, raised $3.5 million more in venture backing from 3i and Common Angels.

This is a very competitive sector.

But Carbonite is a useful product, so see below for full press release, sent to VentureBeat yesterday:

Carbonite, Inc., the leading provider of simple, inexpensive, automatic PC backup over the Internet, today announced the close of its Series A, phase 2 investment round. Venture and private equity firm 3i led the round, with additional participation from previous investors including Common Angels. The latest round brings Carbonite’s total venture funding to $6 million. The company will use the proceeds for ongoing marketing programs supporting its automated, Online PC Backup product as well as infrastructure development.

As few as 3 percent of PC users backup their data on a regular basis. What’s more, Carbonite research assessing customer experiences prior to installing the company’s online backup solution reveals that 87% of respondents had lost data, and 80% of those respondents categorized their data loss as either a “hassle” or an “outright catastrophe.”

“Industry reports anticipate that sales of digital still cameras alone will be 29.1 million units in the next two years,” said 3i’s Jiong Ma. “Then consider other market elements such as portable music players, multimedia cellular devices and basic PC or laptop purchases. When combining the files from those consumer devices and others not even mentioned, we are looking at an enormous amount of consumer digital files that require safekeeping. Carbonite’s business model, with its accessible distribution channels and non-intrusive technology, seems to be the right answer to a growing problem.”

Launched in 2005 by serial entrepreneurs David Friend (CEO) and Jeff Flowers (CTO), Carbonite addresses the all-too-common consumer struggle with losing personal computer data. Online PC Backup offers unlimited storage capacity at an affordable price and is easy to use. Simply set and forget: Carbonite’s software detects an idle Internet connection and gets to work backing up new and modified files. File icons in Windows “My Computer” are tagged so that users can quickly determine what has or has not been backed up. File recovery is equally as simple.

“Our investors understand that we live in an era when people save their whole lives, everything from entertainment to finances, on their PCs,” said David Friend, CEO and President of Carbonite. “The possibility of losing that data is rarely considered until we come home one day to find everything gone. Why take that risk when security and Internet technologies can solve the problem painlessly?”

Carbonite backup, offering unlimited storage space, is currently available at Amazon.com, J&R Music & Computer World, and Staples as well as online at www.carbonite.com. Subscription rates are only $49.95 for one year and $89.95 for two years.