BOSTON--(BUSINESS WIRE)--SessionM, the market leader in mobile-first loyalty and engagement solutions, today announced that it has closed a new $12M investment round led by Causeway Media Partners, a growth equity firm focused on investments in technology and media relating to sports founded by Boston Celtics principal owner Wyc Grousbeck, with additional participation from NTT Docomo Capital, Commerce Ventures and existing investors Highland Capital Partners, Charles River Ventures and Kleiner