The appointment comes as Racing UK renews its focus on maximising the potential within its consumer database.
It has tasked Gravity with improving prospect conversion, reducing churn and driving re-engagement with lapsed consumers.
Nick Mills, commercial director at Racing UK, said: "We were not only impressed with Gravity's previous experience in CRM but also their passion and desire to get under the skin of our business and consumers.
"CRM is going to be critical to the business going forward and in Gravity we have a partner who can help us deliver a best in class solution."
Stephen Firth, managing partner at Gravity, said: "Racing UK are an exciting company operating in a dynamic sector and we are looking forward to developing some great work with them."
Gravity was launched in September 2007 by Firth and Andrew Roberts, formerly client service director and head of promotional marketing at Chemistry. Its clients include Scottish & Newcastle, Ferrosan, Intertissue Sofidel and The Student Support Centres.