Just read an article at Business Insider about Hinge.
It says "Our new data scientist used to work for the CIA, catching bad guys," ... "And now he's working on this new algorithm. It's a new world."
Compatibility is STRICT PERSONALITY SIMILARITY and not "meet other people with similar interests"
As for Tinder, it is backed by IAC, which owns Match, Chemistry, OkCupid, Meetic, Tinder, Twoo and others.
Tinder has not any revenue. It is free because Tinder and Twoo, are marketing tools to migrate free users to Match/ Meetic and make them pay there. It seems other social dating applications are decaying like Badoo, Zoosk (planning 2014 IPO), Skout, Twine, AreYouInterested, etc.
Social dating is vaporware. Online Dating for serious daters does not need to be more social, it needs to be more effective/efficient. It needs to reduce the false positives problem.
Remember failed ones? like: LikeIt / TheCompleteMe, Comiingle, LikeBright, Perceptual Networks, Zingl, Engage (then rebranded to Ignighter group dating, then rebranded again to StepOut), Thread, Triangulate, Gelato (then rebranded to Twnty), WooMe, 12Like, LittleHint, SmartDate and others.