Sounds really cool. I like services that offer solutions that are easier along the dimension of horrible-awkward-interactions. I.e. I think that maybe the biggest appeal of this is not actual the time saved finding the person at a time when they have the right cash on hand, but the fact that Mint will send the email for you in a clean, impersonal but not menacing manner.
I haven't tried this or Venmo but I think it would be cool if they added some sort of group portal service, where you could email a group of friends, say for "Dinner: $96", and then Mint would email all of them with a link to a spreadsheet/form of some kind where they could list what they've already paid each other, other related grievances that would affect how much they owe, etc. And then once all had approved the resolved list of payments, the process would proceed on an individual level as normal with the correct amounts.
I haven't tried this or Venmo but I think it would be cool if they added some sort of group portal service, where you could email a group of friends, say for "Dinner: $96", and then Mint would email all of them with a link to a spreadsheet/form of some kind where they could list what they've already paid each other, other related grievances that would affect how much they owe, etc. And then once all had approved the resolved list of payments, the process would proceed on an individual level as normal with the correct amounts.