Just stating a few conclusions that I’ve drawn based on my own experience (…a lot of it is professional, lol) and this article. And please note there are some inaccuracies and somewhat important omissions in that Verge article. You have to take it with a grain of salt. At the same time because I am professionally tied, you can take this post with a grain of salt too, but you really have to know your messaging to get where my bias is.
If ecosystem (and maybe a better way to phrase it is “console-ification”) of personal electronics is evolving into competing walled gardens, we will need uniform/shared protocols in order for them to communicate with each other. Today, here are some of the leading standards:
Addressing: URI, email addresses, phone numbers
Transport protocols: HTTP, SMS (ie., SMPP), XMPP, email (SMTP etc)
The unfortunate thing about this is that when XMPP/IM was implemented, the federated model kind of, well, doesn’t work. It is more thinking like a local network.
WhatsApp and other mobile messaging services are successful today because they address based on phone numbers, not email or URI. Price is second to convenience and ubiquity, because XMPP clients on mobile phones has been around since a long time ago and those were free too. But that enabled people to send messages only to other people using the same service–think BBM. BBM is actually a good example as to what else WhasApp (and others) are doing right, but fundamentally by allowing phone numbers as addresses, it makes everyone a part of your system.
Rich Communication Services (RCS) is a real thing that carriers have been working on since 2007 (if not earlier), but obviously doing it top-to-bottom is a lot slower than a small company trying to disrupt. But as you know with carrier-branded mobile phones that sells for nothing with a 2-yr contracts, it can be a pretty powerful competitor in this space. This is where pricing matters.
Ultimately, what people pay for their cellular service is more or less entirely up to the carrier to determine. If you think paying $5 or $10 or $20 for however many text messages you send a month is too much, well they could just bump you into a new pricing paradigm and give you unlimited texts or a bucket of texts a month, rolling up the built-in cost to the core price of the new package. AT&T has done this already. But because of the way text messaging pricing has been set by US carriers, it’s becoming a sore point that further allows platforms like WhatsApp to expand in this way. Because, it’s free OTT messaging to people not using the app, and since it confederates based by phone number, it’s just data for the rest.
Since nobody is going to give up their user DBs, phone numbers will be the reliably #1 way to identify people, and become a key property for unified messaging. And invariably that means you need a carriers’ blessing to get this to work. That might mean, at the very least, have people sell phones to run your software (iMessage is a pretty solid first step).
RCS is really just a more carrier-friendly version of this. Which only means in order to compete with WhatsApp and the like, it require the same business and marketing approach–not expecting much there. More likely that someone buys them out first.