1. Latency. We really needed messages to go out to everyone all at once.

2. My personal phone became unusable for the rest of the event because people thought that number was a general event organizer contact mechanism. This was a big deal because I was a key member of the operations staff and really needed my phone to be useful.

Solving (1) and (2) was certainly doable, but twilio solved the problem for us and I had higher impact IT stuff to be working on for the org.