It is commonly called ACH. It became more popular after 9/11.
If I remember right, one of the problems during that time was when the planes were grounded, checks that are flown to clearing houses could not fly. This disrupted banking institutions. One of the solutions that came from the 9/11 commission required that all banks go electronic so that it never happened again.
I could be a little wrong on the story (As I get older I am get more and more of the sometimers disease)
Here is a link that can explain it better. But I agree with YorkieMom55, you set the rules for your business.
http://www.nacha.org/About/what_is_ach_.htm
Good Luck