The Riverside Company, a private equity firm, completed the investment in Apollo Interactive, an operator of full-service marketing and advertising agency. Financial terms were not disclosed. “We’re excited to partner with the Apollo team and provide value in a number of ways. During our partnership, we plan to consummate one or more strategic add-on acquisitions, deepening Apollo’s reach into existing products and verticals, as well as expanding into new markets," Jeffrey Gordon, The Riverside Company Managing Partner and Co-Fund Manager.