[crottypeter]

Just checked my provider's pricing ( in the UK) MMS are capped at 300kB and cost 30p (0.39 USD) per message.

That kind of pricing made WhatsApp an infinitely preferable alternative.

Phones automatically switching to MMS would be catastrophic.

Data (WhatsApp) is essentially free in comparison. £10 (13 USD) per month gets you 20GB: which doesn't care how many messages/recipients/photos you send.

[vel0city]

Dang, that's some highway robbery pricing right there.

Here in the US its common to have at least 1MB MMS max size. Back in the day 300-600KB was often the max size, but that's definitely changed over the years. Maybe its just splitting it up and re-assembling it behind the scenes, I'm not sure.

I can't speak for all history, but from about 2004 or so in the US MMS and SMS were often bundled and billed the same, especially for networks which had rolled out 3G/EV-DO. Having a plan with 500 messages usually meant 500 combined SMS and MMS message.