Mark Johnson, President & CEO of Loyalty 360, asks attendees of CRM Evolution, held in New York, August 8-10, 2011: "What is the most difficult challenge brands have today in creating engaging customer service?" Respondents are Vinay Iyer, SAP, Rebecca MacDonald, Attensity and Steve Chirokas, VoltDelta, LSSiDATA. We invite you to share your thoughts below.