I think services like Venmo are the way of the future, but there's something the minimalist in me really likes about the completely analog transfer of paper money. There's an app for everything and they all require mental overhead (the least of which is remembering which silly oft-nonsensical app name translates to the real-world thing you want it to do). I'm not a Luddite, but simplicity to me is not 100 different apps for 100 different everyday tasks they handle.