"For over 10 years, we have focused on making it easy for consumers to find and buy products online and help our clients grow their business," said a blog post from the group.
"We've worked with Google for years, and look forward to the great things we will be able to do together."
Rob Wight, founder and chairman of Channel Intelligence, said: "Our vision for CI started with the desire to simplify the online shopping experience... I am very proud to see our vision executed to this great outcome."
The move marks Google's latest effort to expand its retail capacities. In November, Google said it was buying Canadian start-up BufferBox, which manages self-service parcel lockers to help consumers avoid missed deliveries.