[akersten]

Why can't that just be a "normal" or whatever SMS from the carrier? I've got a contact named "Sprint" in my phone with their automated stuff, I assume those are not Flash type messages. I actually turn notifications off for that contact because I don't care to see them.

[derefr]

Probably legacy reasons. Flash SMS was designed in a world where phones had teeny-tiny amounts of storage. So there were regular SMSes—that were only supposed to be ACKed once they were persisted to disk (or to the SIM card!); and then there were flash messages, for realtime, ephemeral, if-you-miss-it-it-doesn't-matter messages. Sort of the textual equivalent of RTP packets.

[morpheuskafka]

It probably made more sense in the days when carriers closely controlled the phone's UI and there weren't other apps that could be interrupted by such a popup.