If you are going back and forth often and end up spending more time than half the time south of the border, it might just work for you :)

Here is a quote from their fine print

> Not for extended international use; you must reside in the U.S. and primary usage must occur on our U.S. network. Device must register on our U.S. network before international use. Service may be terminated or restricted for excessive roaming or misuse.