McNamara will focus on innovation at Occam and head its analysis, list broking and data planning teams.
He has more than 14 years of customer insight experience, having worked for ClarityBlue and Equifax as well as on the marketing side with NatWest, Orange and Lloyds TSB.
Before joining Occam, he was working as a consultant to Abbey on the development of its credit card business, having left ClarityBlue in March.
He joined ClarityBlue as strategy director in late 2004 from Lloyds TSB, where he was responsible for establishing the CRM systems for its own brand, Goldfish and third-party branded credit cards.
Scott Logie, managing director of Occam, said: "As the business grows we need more big hitters and Ian's experience speaks for itself. He's an expert in dealing with big teams, big budgets and big names and I am confident he will make a significant contribution to the business."
Occam employs around 100 staff and its clients include Eurostar, Nationwide, Air Miles and British Gas.
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