There is no question that challenger banks like Revolut, Monzo and N26 have acquired massive amounts of customers; it leads to the question of whether the big banks should be concerned about losing customers altogether; a mobile advertising technology company called Ogury recently looked at mobile banking behavior of 688,000 people in the UK; what they found is that the traditional banks still have a larger market share and also have more faithful customers; Monzo ranked the highest exclusive customer base among challenger banks at 22%; the Financial Times digs further into the idea that customers are simply leveraging the challenger banks as secondary accounts. Financial Times