Three years ago this month, Google Inc. launched a new social network with high hopes of countering the rising tide of Internet users who were flocking to Facebook.

That hasn't happened. But experts say Google Plus has served a valuable purpose for the giant Internet company as the centerpiece of a broader strategy to create a unified profile for each person who uses any of Google's online products — the better to deliver more targeted advertising, which is highly profitable for Google.

And despite speculation fueled by the resignation of longtime Google Plus boss Vic Gundotra, the company says it has no plans to abandon the service. "Reports of our death have been greatly exaggerated," said David Besbris, a Google engineering vice president who took over Google Plus when Gundotra left two months ago.

In his first public comments to a reporter since Gundotra's departure, Besbris said in an e-mailed statement that Google Plus has "hundreds of millions of users (and growing)." He vowed: "We're committed to building a product that people absolutely love. So no, Google isn't giving up on Google Plus."

Google declined to make Besbris or Bradley Horowitz, a longtime Google Plus vice president, available for a formal interview. Gundotra hasn't publicly explained his departure from the company, though by all accounts he left on good terms.

In his statement, relayed through a spokesperson, Besbris described Google Plus as both a social network and "a social fabric on and off Google."

The latter refers to Google's efforts to make Google Plus serve as the identity that people use for signing into other Google services and independent applications, as well as to comment on YouTube and endorse or share things they find on other websites.

Google says this helps the company provide a "more consistent experience" to users — for example, by anticipating that you want directions on Google Maps for the restaurant you found with Google's search engine, then letting you review the meal on Google Plus.

Analysts say it also lets the company compile a more complete picture of a user's habits or interests, by recognizing them on a variety of services and devices, which in turn helps Google show more relevant advertising. The biggest part of Google's $60 billion in annual revenue comes from ads tied to Internet searches, but it's increasingly selling other types of online ads, too.

"The more they can combine what they know about people, across all different channels, the better understanding they have for each user, and that's vital to their ad sales efforts," Forrester Research analyst Nate Elliott said.

Google hasn't released user statistics since October, when it said 540 million people worldwide used Google Plus credentials to sign in or post comments on any Google service in the previous month. A smaller group of 300 million visited "the stream" of Google Plus itself.

By comparison, Facebook boasts 1.28 billion monthly active users worldwide, although that reportedly includes people who click a Facebook icon to "like" or share something they find on another site while signed into Facebook.