Tinder and Hinge parent Match Group faces an activist investor campaign that wants the dating app giant to either overhaul its business or explore going private.Starboard Value, which revealed Tuesday that it has built a 6.6% stake in Match Group, is in ongoing talks with the company and its board regarding ways to boost profitability and cut costs, the activist fund’s boss Jeff Smith said in a letter.Smith argued that Tinder has suffered from a “lack of innovation” that has hurt its growth despite a base o ...