As Friendster, MySpace and many other social-networking sites have discovered, a successful business finds a niche that draws in a large number of users and offers intriguing, easy-to-use services that keep those users interested. Whereas Facebook, LinkedIn and Twitter have excelled at this formula, Google's efforts in this area—Buzz (2010), Wave (2009) and Orkut (2004)—have faltered. The search-engine giant hopes its search is over with this week's introduction of the new Google+ (Google Plus) network.

Google+ is an attempt to let users establish and maintain relationships online, much like Facebook, but with slicker, more intuitive user interface and several of options designed specifically for mobile users. The company can also integrate its dozens of well-known services—Gmail, Google Docs and Google Maps, to name a few—within the larger Google+ framework.

Google+, which is still in development and not yet widely available (you need an invite to take it for a test drive), currently has four main components: Circles (a drag-and-drop interface for organizing contacts); Sparks (an interface for listing your interests and sharing them with others); and Hangouts (a video chat room), along with mobile features. The mobile portion of Google+ includes apps that allow users to add their location to every Google+ post (+Location, location, location), automatically add photos to a Google-hosted online photo album (+Instant Upload) and organize group texting sessions among multiple contacts (+Huddle).

With Google+, the company is betting that the group structure, where Facebook has always been weak, is a place it can find traction, says James Hendler, assistant dean of Rensselaer Polytechnic Institute's (RPI) IT and Web Science and Computer and Cognitive Science departments. "By coupling this to Gmail and Google groups, where they have a commanding lead, they believe they will have something different enough people will use both," adds Hendler, who is also chairman of the Tetherless World Constellation, an RPI group that explores the research and engineering principles that underlie the Web.

With Google+, the company is clearly betting that they will either capture enough market share from people who are not yet using any networking (essentially the way they made chat more available through Gmail) or that it will be different enough to keep people on site in between Facebook visits, Hendler says. "Note that Google+ will win if it can get people to spend more time on the Google site, the way Gmail does, since Google can only really use the data it has on users in it's own space," he adds. "They are betting +Circles and +Huddles will be the winners that get the users to stay and share."

Whereas Google has not set a date for Google+ to go live for all Web users, the project is a direct challenge to Facebook's supremacy in the social networking world. Facebook claimed to have more than 500 million users as of July 2010, with each user having an average of 130 "friends". More recent estimates put the user base well over 600 million.

Whether this is an opportune time for Google to renew its surge into the social networking space is debatable. A Web site that tracks Facebook activity earlier this month indicated Facebook had lost six million U.S. users in May, a claim that the company disputes. Either way, Facebook recently gained a powerful ally in the mobile space. HTC's new Status handset features a dedicated Facebook button that facilitates instant sharing photos, videos and information on that social network. HTC has not yet announced a release date or pricing for the phone, which, ironically, runs on Google's Android operating system.

MySpace also crept back into the news this week as News Corp. announced it would sell the once-influential social-networking business for $35 million, including a private equity stake in Specific Media, a company that specializes in online advertising. The MySpace site, which is a shell of the business that News Corp. paid $580 million for in 2005, has bled visitors over the past few years, down to 35 million in May, according to tracking firm comScore, Inc. There is a bit of a silver lining, however, as pop star Justin Timberlake is partnering with Specific Media on the purchase and will play "a major role in developing the creative direction and strategy for the company moving forward," according to a company press release. Perhaps MySpace will even go back to its roots as a place where musicians can promote their work and interact with fans.

Did Google get it right this time? "That is, of course, the billion dollar question," Hendler says. "Most of us don't, see Google+ as a Facebook killer, but rather a new play aimed at a still open place."