[josephjrobison]

I think it depends on the circles you run in. I think clusters of friends and family members probably use different services. My extended extended group of 100+ people all use Venmo (can tell by activity in Venmo feed).

That being said, I ran into someone recently who uses Square Cash with all her friends, but that's the first person I've hear using Square Cash (I downloaded it when it came out but no one else was using it.)

A very interesting real-world example of the network effect among second tier services. Second tier as is not FB, Pinterest, LinkedIn.