I have an iphone 5 through AT&T with unlimited text and I need to figure out how to do mass text msg to a very large group of phone numbers. Trying to do a little marketing for my small business. After analyzing past phone bills I've got somewhere between 5-10 thousand phone numbers I'd like to send a mass text message to once a month. As this number is so large doing it through the phone itself would take just way too long, so using some kind of alternative mass text method would be my only option. Can anyone give advice on how I can use the net to send text messages to this many people? If it turns out this would only be possible through another carrier I would probably switch. I'm open to anything. Thanks.