The service, available through Expedia, will enable travelers and vacationers to send postcards via the web from their holiday destinations to friends and family at home.
Users of the service can select their postcards from an online card rack. The postcards are branded or sponsored by advertisers, allowing them to increase awareness both online and offline.
Paul Edney, managing director at Keekaboo, said, "Expedia.co.uk travelers will provide a strong flow of travel oriented consumers to Keekaboo's travel postcard section. Advertisers who sponsor postcards on our site have a powerful and cost effective marketing tool that directly targets the lucrative travel audience."