The agency was appointed to the business after a competitive pitch and has been given a brief to integrate the brand’s SEO activity with its wider marketing communications strategy.
Comparethemarket.com’s relationships with VCCP, its ad agency, and ZenithOptimedia, its media agency, are not affected by this appointment.
Mark Vile, the marketing director at Comparethemarket.com, said iCrossing’s "wealth of experience in search and expertise in digital marketing" would help Comparethemarket.com to "further strengthen [its] position and drive growth for [the] brand in a competitive market".
The digital marketing agency is owned by Hearst Corporation. Its client's include the Coca-Cola Company, LG Electronics, The Lego Group, Heathrow and M&S Bank.
Mark Iremonger, the chief strategy officer, iCrossing UK, said: "Comparethemarket.com is a much loved leader in one of the most competitive search categories in the UK.
"There has never been a time when there is a greater need for the UK public to save money on a range of products, so we are delighted to help Comparethemarket succeed while at the same time making it easy for people to save money."Follow @MaisieMcCabe