In the time that I've been running
http://www.iusecoins.com, I think I've noticed (though I've yet to run a statistical analysis to confirm it) that sales seem to mostly come when the value of btc has been relatively stable, while the volume seems to drop to quite a low level when the currency is making big moves. My guess is that people want to wait and see how high it will climb, but once 12 or so hours of stagnation have passed, they begin to think about spending. Have any other businesses out there noticed similar (or contradictory) patterns?