My recollection is that normal cubesats generally don't have any propellant (as they're usually hitchhiking on larger payloads) so that combined with their tiny size, the orbit is not going to be sustainable for long.

Their website[1] suggests that the price will be around $250,000, in the same ballpark with other launch options. The real selling point is supposed to be quick lead time (months instead of years) and the ability to send payloads with, say, volatile propellants, that other customers would not want close to their satellites.

[1] http://cubecab.com/cubesats.html

Hopefully, these little satellites fly low enough to fall down in a few years, rather than becoming space-spall fodder.