Maybe the problem was with the example? One application I could see for this is maybe being at a conference and entering into a drawing. Instead of filling out a paper form or standing at a kiosk or having to go to a web page and type in some auth code, you just have to send a single text message and you're done.

I can see some applications, and knowing the cost of the administrative portion of promotions, making it easier to be an expert at it definitely has monetary value.

I've been to many (tech-focused, admittedly) conferences that handle this through RFID tags or simple barcodes embedded in the conference badges, the advantage to that system being that attendees don't have to do anything more complicated than hold up their badge to a badge-scanning attendant.

I feel like there's a fantastic use case for the parent's project; I'm not quite sure what it is yet.

You're right... I'm trying to figure out how this can be useful. I used it at a recent Meetup to divide people into committees, and that worked well. But yeah, the hunt for more use cases is on.