Edit: draining to $0.00 is OK, as jonathan explains below.
Draining the card to the penny is not weird. If there is $10 on the card and your purchase is $11.50, $10 will be removed from the card and you have to pay the remaining $1.50 some other way.
Expected behavior :) j
http://twitter.com/#!/jonathanscard/status/10034195955777536...
http://twitter.com/#!/jonathanscard/status/10035604975584460...
edit: now at least 5, see above
I see what you're saying, and of course it is possible that some jerk is buying gift cards with the card.
That said, it's worth pointing out that the tweet stream is not real time and it doesn't have every transaction. The card balance is scraped from the sbux site every minute and posted to Twitter if it has changed since the last tweet. When there are multiple transactions in the same minute, the changes get aggregated. This can result in some strange looking numbers.
What I think we're learning here is that if someone wants to reload the card, lots of little transactions over time is better than one big one. Or, perhaps the balance should not be tweeted.
Thoughts? j
The balance is really neat to see and it keeps people engaged and thinking about this project, even if they're not actively partaking (like myself, at the moment).
The smaller installments of cash also help others realize that it's okay to submit small amounts and increase the likelihood that more than just one person with a large purchase will benefit.
What I'm wondering is if you can have a deposit-only card, which transfers funds to the live card to keep it topped up at $10. Downside is some people have to wait an extra minute or two for free coffee; upside is someone trying to clean out the account has to spread it over a bunch of transactions, which even if it doesn't stop everyone probably raises the barrier to entry.
A PayPal account could also work for this.
Then you could broadcast a rough total balance, and just have a binary indicator for when the live card gets topped up.
But since that's kind of a hassle, then you'd whip up a quick app that lets people easily amortize a larger contribution over a series of coffee-scale contributions. Connect that to their twitter account, and you can credit each individual coffee donation to an individual and report them individually.
It's effectively the same as having a larger account balance, but since you're not holding the money it feels more engaging and social for folks.
I will strenuously avoid this turning into anything resembling a bank - it needs to be more like a "take a penny, leave a penny" tray sitting on a Starbucks counter. If someone want to be a jerk and empty the tray into his pocket, so be it. They're just a jerk who I'm sure will get what they deserve in life.
Fingers crossed, j
The beauty of this is that one person can't ruin the fun for everyone involved. Call me a hopeless romantic, but I think people who don't get the concept are in the minority. Their behavior will be overrun 100x by people who do get the concept.
We'll see what happens soon enough... j