Having the location sent every x minutes by SMS is not the same as web tracking, though. 
Just consider this: an SMS every 5 minutes makes 12 text messages per hour. I could run out of credit, or the thief could notice the charges, or they could remove the SIM card, or they could move to an area with no cell coverage. Many things could happen, who knows! Activating web tracking too, as soon as possible, would give you one more chance to find your precious device.
Besides, web tracking shows all the locations on a same map, on a time line, and that’s pretty useful.
I really don’t see a reason for not allowing to start web tracking too, possibly as an option, when you send a LOCATE sms command to your phone.
