Try to guess America’s most engaging social network. Twitter? Wrong. Facebook? Wrong. Pinterest? Wrong. Google Plus? Wrong again. According to comScore‘s latest social networking statistics, for the month of March, the San Francisco based site Tagged engages users like no other social networking service.

According to ComScore data, each time a Tagged user visited the site, he or she stuck around for 12.1 minutes which trailed only Tumblr (14.7 minutes) and defeated Facebook (10.9 minutes). Also, Tagged users visited an average of 18 times each day during March, next to Facebook’s average of 36 visits per vistor.

Tagged co-founder and CEO Greg Tseng says he’s happy about ComScore’s March data, but that his company has been among America’s most engaging social networks for about a year now. The secret to Tagged’s success? A pivot Tseng and co-founder Johann Schleier-Smith made around the beginning of 2008.

The old friends began Tagged in 2004, at the time angling it to be a Facebook-like social network for high schoolers. Eventually, nevertheless, Facebook augmented besides a closed college network and enabled everyone over the age of 12 to join the network.

“We took a hard look and decided we weren’t going to win,” Tseng says. “But we had found out a lot of our users were actually using Tagged to meet new people, so that led us to pivot into a new space called ‘social discovery,’ where people use sites to make new social relationships.”

As confronted to sites like Facebook, where users generally systematize and manage relationships developed offline, Tagged functions mainly as a portal to meet new people online for simply friendship or romance. The site’s algorithms motivates users to connect based on shared hobbies , interests & tastes.

Tseng says Tagged’s 10 million core monthly active users form an average of 100 million new connections per month. The site has been profitable since 2008, and over the past year tripled its staff to a current count of more than 170.

With social invention as a whole seen by many to be a mounting tide, Tseng believes Tagged’s accomplishment will persist to grow.

“If I look out at the next five or 10 years, I really see social discovery as big as social networking — in some sense I think you can think of social discovery as the engine for social networking,” he says, referencing Dunbar’s number, which theorizes that humans can maintain an average of 150 connections at a time.

“Facebook is the place where you maintain your current 150,” he says. “And Tagged will be the place where you refresh that 150.”