The Plus in Google Plus? It’s mostly for Google

San Francisco – Google Plus, the company’s social network, is like a ghost town. Want to see your old roommate’s baby or post your vacation status? Chances are, you’ll use Facebook instead.

But Google isn’t worried. Google Plus may not be much of a competitor to Facebook as a social network, but it is central to Google’s future – a lens that allows the company to peer more broadly into people’s digital life and to gather an ever-richer trove of the personal information advertisers covet. Some analysts even say that Google understands more about people’s social activity than Facebook does.

The reason is that once you sign up for Plus, it becomes your account for all Google products, from Gmail to YouTube to maps, so Google sees who you are and what you do across its services, even if you never once return to the social network itself. Before Google released Plus, the company might not have known that you were the same person when you searched, watched videos and used maps. With a single Plus account, the company can build a database of your affinities. Google says Plus has 540 million monthly active users, but almost half do not visit the social network.

“Google Plus gives you the opportunity to be yourself and gives Google that common understanding of who you are,” said Bradley Horowitz, vice president of product management for Google Plus.

Plus is now so important to Google that the company requires people to sign up to use some Google services, like commenting on YouTube. The push is being done so forcefully that it has alienated some users and raised privacy and antitrust concerns, including at the Federal Trade Commission. Larry Page, Google’s chief executive, tied employee bonuses companywide to its success and appointed Vic Gundotra, a senior Google executive, to lead it.

The value of Plus has only increased in the past year, as search advertising, Google’s main source of profits, has slowed. At the same time, advertising based on the kind of information gleaned from what people talk about, do and share online, rather than simply what they search for, has become more important.

Brand advertisers already target ads based on assumptions about broad categories, like women who watch sports. But the ads can be even more targeted when Web companies know more about their users – say, that a particular female soccer fan is also a mother who likes thrillers and wants to buy a home.

“The database of affinity could be the holy grail for more effective brand advertising,” said Nate Elliott, an analyst at Forrester studying social media and marketing.

Google says the information it gains about people through Google Plus helps it create better products – like sending traffic updates to cellphones or knowing whether a search for “Hillary” refers to a family member or to the former secretary of state – as well as better ads.

“It’s about you showing up at Google and having a consistent experience across products so they feel like one product, and that makes your experiences with every Google product better,” Horowitz said.

Thanks to Plus, Google knows about people’s friendships on Gmail, the places they go on maps and how they spend their time on the more than 2 million websites in Google’s ad network. And it is gathering this information even though relatively few people use Plus as their social network. Plus has 29 million unique monthly users on its website and 41 million on smartphones, with some users overlapping, compared with Facebook’s 128 million users on its website and 108 million on phones, according to Nielsen.

The company has also pushed brands to join Plus, offering a powerful incentive in exchange – prime placement on the right-hand side of search results, with photos and promotional posts.

“It is literally promotion that money can’t buy,” Elliott said. “It is something that Google could make billions off of if they sell that space tomorrow, and they’re giving it away to try to get people onto the social platform.”

Starbucks, for instance, has 3 million followers on Plus, meager compared with its 36 million “likes” on Facebook. Yet it updates its Google Plus page for the sake of good search placement and in doing so uses tutoring from Google representatives on how to optimize Plus content for the search engine.

“When we think about posting on Google Plus, we think about how does it relate to our search efforts,” said Alex Wheeler, vice president of global digital marketing at Starbucks.

The Economist has more fans on Google Plus than on Facebook – 6 million versus 3 million – and its journalists use Plus features like Hangouts. Yet Chandra Magee, The Economist’s senior director of audience development, emphasized the value of Plus as a search engine optimization tool.

“There is potential there to help us get in front of new audiences,” she said. “But it also helps with our SEO strategy because our posts on Google Plus actually show up in our search engine results.”

The way Google is tying its search engine, which dominates the market, with a less popular product in Plus has set off antitrust concerns. The Federal Trade Commission raised the issue during its recent antitrust investigation of Google, according to two people briefed on the matter. That investigation closed without a finding of wrongdoing.

“If you want Google search, they’re going to shove Google Plus at you pretty hard, so the consumer’s forced to take the product they don’t want to get the product they want,” said Tim Wu, a professor at Columbia Law School who studies antitrust law and the Internet.

“That raises big questions under antitrust law,” he said. “It reminds me a little bit of Microsoft when Microsoft was fearing Netscape and decided to bend over backward and do anything possible to tie Explorer to their operating system.”

Google declined to comment on this issue.

Some Google users have been turned off by the push to sign up for Plus. Melissa Bright, a business analyst in Houston, stopped using some products because she did not want to join.

“It just seems really intrusive and easy to accidentally find yourself sent to it at every turn,” she said.

After YouTube began requiring a membership to comment on YouTube videos, a founder of YouTube, Jawed Karim, deleted much of his account. And YouTube’s most popular video creator, who goes by the username PewDiePie, temporarily shut off comments on his videos.

Commenting on consumers’ reactions to Google Plus integrations, Horowitz of Google said, “We are attuned both to what people say and to what people do.”

And despite what some vocal users have said, few have fled – a sign, perhaps, of Google’s sheer strength on the web.

“If people want to use your platform enough,” Elliott said, “you can get away with quite a lot.”