The US firm, which has five million registered users - 90 per cent of whom are US-based - says anyone with a mobile or PC can receive a greeting card, but they must be a MocoSpace member to send one.

Justin Siegel, CEO of MocoSpace, said: "With each passing year, the mobile phone becomes more central to our lives. We work very hard to deliver a great service to our community of over five million members and they reward us with their enthusiasm and engagement."