Exactly. If people are offered something they have no interest in buying, then they aren't going to buy it, regardless if it's the greatest payment method known to humankind.
Enter Bitcoins.
Excellent observation, Synoptic. Now for extra credit...
! interested(x) --> ! Buying(x)
Buying(x) --> Interested(x)
x = bitcoin
! Buying( bitcoin ) --> ?
And if I could only remember where I last saw my discrete math textbook, I could prove it!