I don't completely understand that story. Why didn't they start babysitting for half a coupon?
Would there be any economic difference between (1) the couples all deciding to babysit for half a coupon and (2) doubling the number of coupons each couple has? The two choices seem functionally equivalent to me but I might be missing something.
Tangential, but a subject of some local interest:
Why Bitcoin will fail by Avery Pennarun. "The sky isn't red." Thesis:
I'm not sure I buy these and am not competent to evaluate his claims on 3., but would like others' critique.
L019: Bitcoin P2P Currency: The Most Dangerous Project We've Ever Seen by Jason Calacanis. A rather more enthusiastic viewpoint of the project:
The actual text contains many more caveats than the eye-catching selection of points above.