Mobile data in Mexico?

I checked the cost of using my phone in Mexico last January before we left Canada. $15 per day, I think it was. Outrageous. More per day than a month of Mexican service. So I went straight to the cell store when we got off the plane and bought a sim card and it was great...service and convenience and cheap. 79 pesos for a card and 200 pesos for a month of North America free phoning and I think 1 gig of data. The phone must be unlocked before you leave home.