A Facebook for patients: the Holy Grail? We talk to Dr Mohammad Al-Ubaydli, the founder of Patients Know Best, a cloud-based system that allows patients to aggregate and share their medical data with medics and others. The system appears to have achieved lift-off, with tens of thousands of users across the UK and the USA. Al-Ubaydli claims that over 90% of patients offered the service take it up. Meanwhile, Patients Know Best is preparing for 2013, when it will roll out its service to a county of 1.6 million people in the UK. To top it all off, Al-Ubaydli is now looking for capital to make the leap abroad. So, how has he succeeded where Google, Microsoft and the NHS have failed? And how will this enable the development of new business models?