The acquisition follows the Chief executive David Perkins also left the agency at the same time.
Linnaeus specialises in customer engagement through digital and mobile channels. The team will be fully integrated into the Indicia business along with their suite of web and mobile products, which will be merged with Indicia's existing digital services.
Mike Fisher, a Linnaeus director, will join the Indicia board as chief futurist and will be responsible for demonstrating how insight and technology can engage and connect customers with brands.
Ryan Shannon, part of the original Linnaeus management team, will also be joining the Indicia board as managing partner. He will operate within the client services team and will continue to develop and service both Indicia and previous Linnaeus clients.
Ian Stockley, managing director at Indicia, said: "Following the integration of Entire and Marketing Databasics at the start of the year, bringing the digital and mobile expertise of Linnaeus into the company increases our expertise in this rapidly growing area for our clients.
"The role of chief futurist will be instrumental in further positioning us as the leading customer intelligence agency."
Indicia clients include ASOS, Woolworths.co.uk, Sainsbury's Bank, Reader's Digest and Tourism Ireland.