ClarityBlue has strong links to Lloyds TSB after it built the bank's customer database and continues to act as its data buyer.
A Lloyds TSB spokesman said the bank has yet to recruit a replacement for McNamara.
Recruiting McNamara is a scoop for ClarityBlue as it aims to expand its database hosting and client data broking business. McNamara will report to Duncan Painter, ClarityBlue's chief executive.
"I'm pleased with the significant improvements in customer intelligence and customer life-cycle management achieved at Lloyds TSB," McNamara told Direct Response. "But I was attracted by ClarityBlue's reputation and the potential to work across industry sectors. I'm looking forward to working with ClarityBlue to help shape the next level in innovation it provides clients."
McNamara joined Lloyds TSB in 2003 as part of the bank's acquisition of Goldfish where he had established a CRM system. He then embarked on integrating the system with Lloyds TSB's customer marketing systems.
His previous roles included head of customer intelligence for mobile operator Orange, and director of marketing solutions at Equifax, where he partnered with Sand Technology (now ClarityBlue) to develop a prospect management system.
His other senior client role was manager of modelling and marketing analysis at NatWest.
McNamara was recently voted number 23 in Direct Response's 'Power 50 in Data' league.