Communispace, the Boston-based online market research company, announced yesterday that it will merge with the London-based consultancy Promise, which was just bought by its parent company. Promise is a consulting firm focused around customer research.

“We have been watching Promise for years, as they have mastered co-creation and helped executives act intelligently based on what they learned from consumers,” said Diane Hessan, CEO of Communispace, in a release. “Everything about our business is focused on doing great work that matters, and the experience and dynamism of the Promise team is going to help us make our work matter even more for our clients.”

Co-creation refers to a marketing and business strategy centered around insights generated by customers.

The deal will significantly expand Communispace’s London presence, and Promise also maintains an office in New York. Communispace’s headquarters are near South Station in Boston. Terms of the deal were not disclosed.

In 2011, Communispace was purchased by Diversified Agency Services, a division of OmniCom.