To make your wish her command, Siri floods your cell network with a stream of data; her responses require a similarly large flow in return. A study published this month by Arieso, an Atlanta firm that specializes in mobile networks, found that the Siri-equipped iPhone 4S uses twice as much data as does the plain old iPhone 4 and nearly three times as much as does the iPhone 3G. The new phone requires far more data than most other advanced smartphones, which are pretty data-intensive themselves, The Post has reported.

In all, Arieso says that the Siri-equipped iPhone 4S “appears to unleash data consumption behaviors that have no precedent.”

Under most circumstances, this would seem to be someone else’s problem. Cellphone contracts are “tiered” so that those who use a network more than others pay more for the privilege. You want to ask Siri silly questions? Go to town — but you (or, in this case, I) will get the bill at the end of the month. By the same logic, a customer who wants better service on an airline can pay for it by buying a first-class ticket. The marketplace provides.

Except on the data skyway, it’s not that simple. Cell and data networks are like any common resource; they have limits. And once they hit their limit, regardless of which group is using its share and then some, there’s no more to go around.