japan.internet.com recently reported on a survey by goo Research into electronic cash, and found that the most common usage was where being quick was important, such as at train stations, convenience stores, and small transactions to avoid fighting with change.
Between the 17th and 19th of April 2013 1,068 members of the goo Research online monitor group completed a private internet-based questionnaire. 52.4% of the sample were male, 16.3% in their teens, 18.3% in their twenties, 21.9% in their thirties, 16.2% in their forties, 15.6% in their fifties, and 11.7% aged sixty or older.
The numbers do suggest that electronic money is well-established here in Japan. I use one card, only, Hankyu Stacia, from a local railway, department store, shopping centre, baseball team, hotel etc operator, mostly for saving me fiddling about at ticket machines, but also occasionally at convenience stores and rarely at vending machines. It also has the benefit (from my point of view, at least) of being a post-pay system – there is no stored money; they are closer to credit card transactions. Mind you, given that most if not all electronic cash cards tied to credit cards have auto-charging features (that is, when your stored balance gets below a certain point when you pay for something, a debit from your credit card account is automatically added to your stored balance) the benefits of post-pay are I suppose minimal!