The digital arm of the Red Brick Road won the account following a competitive pitch handled in-house by Ebiquity managing director Morag Blazey.
The agency will provide digital consultancy, user experience and website design services to Ebiquity's advertising monitoring division, as the business integrates its services and prepares to develop its online subscription offering.
Ebiquity, which owns Billetts Media Monitoring in the UK, and has strengthened its German advertising monitoring business through the acquisition of Thomson Media Control.
Blazey commented: "Ruby impressed us with their curiosity about our business. They demonstrated an innate skill to translate our rich and complex business proposition into an easy customer proposition."
Ruby managing partner David Miller said: "We really wanted to work with Ebiquity because we both share the same company ethos - a commitment to helping clients derive maximum commercial return from their communications activities. We're looking forward to helping Ebiquity realise the new potential of their enhanced business offering."