Somebody I don't know sent me $50 on Venmo

The note says "Tropical smoothie", and it seems a bit much for a smoothie, but what do I know?

Obviously it's too soon to be thinking about keeping the money. I sent a reply back asking if this was a mistake.

But looking ahead to the future, if I never got a reply, how long is long enough to say "Eh, screw it" and keep the money?

I asked Jenn and her thought was seven days, which certainly seems reasonable, but all opinions will be heard!