Hmm, I think posting the value of the card affects the data points. I understand why it needs to be done, but my thinking is that if nobody knows how much is on there it leaves it less prone to outright abuse.
If the card suddenly gets a $100 recharge I'm sure it will be abused a lot more. Maybe that's part of the experiment, but I'd like to see what people do in general without that knowledge.
EDIT: or maybe even just a "this card has more than <insert cost of minimum item>" so that people know it can be used, but not how many times.
I've been thinking about this quite a bit. One the one hand, last week some jerk saw a $50 balance and spent the whole thing in one shot.
On the other hand, people need to know when there is money on the card if they are thinking about walking down to a sbux to get a coffee.
I might try the "there's more than $10 on the card right now". I've also experimented with delaying the reloaded messages, and doling out the money more directly by asking who wants a coffee.
Folks who respond get the update if they're quick. We'll see what happens, but I believe that there is a sustainable way to handle it.
How about putting everything in units of coffee? "There is at least 1 coffee on me" etc. "5 coffees were just added to me". This might take the emphasis off the amount of money on the card and onto the giving and receiving of coffee.
It would add a level of social obligation. You could go further and require a tweet explaining the purchase. You could even add a little homily about good manners and not being greedy to the explanatory text.
I think you are doing a very interesting experiment with new financial entities, and I'm curious to see where this leads.
The homily sounds like a good idea; that's been shown to actually deter some in the past.
To the other points: how would you go about mandating a photo or any other form of interaction from the purchaser? Jonathan has his card picture posted on the website–Starbucks simply accepts that photo as payment, there's no authorization process in the middle where Jonathan could selectively let some use it while disallowing others.
As a demonstration of the possible, using an image is in the category of Minimum Viable Product, the more sophisticated product would of necessity be an APP that hooked into the existing API and would only show a valid payment code if the Conditions Of Use were met.
This could be a web-app or it could be a native one.
As of the time of this post, ~8:10PM Pacific, "jerk" has been used a total of 6 times in this thread - 5 of which are owned by you! ;-) I write this because this particular comment, for me, sends a negative vibe about you. By no means am I trying to question your intentions or character, but a different choice of word would go a long way.
Now, for the reason I actually wrote the comment: This should be expected behavior. It's quite possible that "jerk" actually needs the help more than the person who gets the one coffee. It's equally viable to assume s/he is simply taking advantage of the system. In the bigger picture, I think these dynamics are completely expected. Would you call the guy that gives $50 or $100 a jerk as well? Either way, it's an experiment, and I wouldn't expect it, given a proper sampling, to deviate much from what we see in society as a whole.
If the card suddenly gets a $100 recharge I'm sure it will be abused a lot more. Maybe that's part of the experiment, but I'd like to see what people do in general without that knowledge.
EDIT: or maybe even just a "this card has more than <insert cost of minimum item>" so that people know it can be used, but not how many times.