I wonder if that momentum will last when Apple Pay Cash rolls out next month - why install a third party app to send money to friends when you can do it via iMessage?
I've literally never heard of Venmo before now
I know for me personally I'm far more likely to say "you get it next time" than bill my friends for some share of an outing. If it's sufficiently expensive that this doesn't make sense I'd just split the check. If I was younger and still a student I can absolutely see the appeal though.