Getting a mortgage is one of the few customer experiences that has, until now, been left pretty much untouched by the digital revolution. You still have to talk to someone on the phone, most likely book an appointment, and then meet with a real person face to face. But a small number of firms are starting to shake this up by going online. This week UK tech startup Habito has launched what it claims is'the world's first artificially intelligent digital mortgage adviser'. But what exactly does that mean?