Swiping right on the 4,500 users in San Francisco who are now using the mobile dating app The League in their quest for true love, venture investors have put $2.1 million in seed money behind the company. With the money, The League joins the ranks of venture- or angel-backed startups like Coffee Meets Bagel, Bumble, Hinge, and the Holy Grail of hook-up and dating apps, Tinder, in answering that age old question: "Don't you want me?" "I was just going to raise a small seed round, but we had a bunch of interest and we went from $500,000 to $2.1 million almost overnight," says chief executive Amanda Bradford. Investors in the round include IDG Ventures, Structure.vc and Sherpa Ventures along with angel investors, including Allen DeBevoise, Naomi Gleit, Mark Leslie, Russ Siegelmann, and Peter Kelly. One additional undisclosed venture fund and an undisclosed angel investor also participated. Bradford says the cash will be used to double its two-person engineering team and continue its very methodical rollout strategy. "I also want to really dominate a couple of markets," says Bradford. "We're going to do a city by city rollout strategy, similar to the Uber strategy. We want to make sure that we're launching really the right way." Although it's just available to the women and men in the city by the Bay, there's a lot of buzz around The League, and a 20,000-strong wait list to get behind its virtual velvet rope from people in cities like New York, London, Los Angeles and Chicago (listed by order of demand). "We hit a really strong need in the market that wasn't being met," says Bradford. "Literally dating apps launch every day in the app store, but we hit a need for young professionals that want to meet each other and don't want the one-night-stand brand associated with their actions." What differentiates The League from the rest (and the thing that opens it up to charges of elitism, classism, and other isms that startups typically don't want to be associated with) is its use of LinkedIn as its data backbone. "Most of the young professional women I know will admit to looking someone up on LinkedIn before they go out on a date," says Bradford. "With The League, we said, 'We know you guys are going to do this anyway and get more information about each other.'" The LinkedIn connection, along with additional information from Facebook, means that anyone's listed colleagues on LinkedIn, Facebook friends, and business connections can't see a profile on the service. Beyond the use of LinkedIn is a sort of "secret sauce" of curation, which is in part based on an invite-only strategy and partially comes from certain profile requirements that users have to meet. "The concept of the curated community really resonates a lot," Bradford says. "if you think about where you meet your significant other at college or through work." Indeed, 28 percent of people met their spouse at college, according to a Facebook report (at my alma mater, Oberlin, I think the percentage is freakishly higher). Moreover, 38 percent of people have dated a co-worker, according to a CareerBuilder report. "If those are the two communities where you're most likely to meet your mate, those are all heavily curated," says Bradford. As for how The League is doing at matching potential mates who can then buy up apartments in the Mission or further gentrify Oakland, Bradford's pretty confident in her results. "We estimate that there have been over 2,200 League dates from 20,000 matches since we've launched," she says. "We've estimated a 25 percent conversion rate when phone numbers are exchanged." Which city is next to pass muster for Bradford's League is dependent on the number of would-be leaguers lining up outside its electronic doors. Right now, New York is in the lead, but Los Angeles and London are also trying to slip the bouncer a twenty and sneak their way in. It's always about demand, according to Bradford. "If the party ain't going to be good don't have the party," she says.