We’ve been hearing for a while now that SMS revenues are drying up as consumers turn to free offerings from social networks, platform providers and stand-alone messaging apps. Facebook is reportedly killing the SMS cash cow, Apple supposedly stuck a dagger into SMS with iMessage, and WhatsApp ate the entire Netherlands.

The Verge was the latest to spotlight the emergence of OTT (over-the-top) messaging services this week with this piece examining the “all-out messaging war” between Apple and Facebook. The Verge rightly notes that messaging has become a key component of both companies’ offerings, providing a way for users to communicate across computers, tablets and both smartphones and feature phones. And the piece claims that Facebook may have something of an edge in this so-called war because of its “platform independence,” enabling messaging across not just hardware but also operating systems.

Lots of alternatives, but no singular threat

But Facebook’s obvious shortcoming in the world of messaging is the same as every other player who isn’t a wireless service provider – it doesn’t allow users to exchange messages with non-Facebookers. Just like WhatsApp, Skype, Google Chat and almost every other alternative, messages can be sent and received only within their respective networks. Apple’s iMessage addresses this by automatically routing messages non-iOS missives through carrier SMS gateways.

Meanwhile, no other messaging offering has achieved the critical mass necessary to threaten SMS on a global scale. Facebook and Skype each claim hundreds of thousands of users, but neither has emerged as a singular worldwide alternative to SMS for mainstream users. Usage of third-party messaging continues to ramp up, but the new services have yet to displace SMS in any substantial way because they’re still niche offerings compared to the much broader world of SMS. Also, it’s no coincidence that no single company or industry has emerged as the primary access point for users’ contact lists – mobile carriers are vying for that coveted spot alongside Facebook, handset manufacturers and carriers.

That’s why SMS usage continues to grow in spite of all the cheaper alternatives. Portio Research earlier this year predicted carrier-powered text messages will increase 23 percent this year to a jaw-dropping 9.6 trillion SMS messages. Portio’s forecast echoes Informa’s prediction that global carrier SMS revenues will continue to grow at a compound annual growth rate of 3 percent over the next five years, generating $723 billion from 2011 through 2016.

What it means

All that is great news for network operators, of course, which will continue to cash their ridiculously SMS checks for at least a few more years. But it also means continued opportunity for mobile marketers who leverage SMS, which remains the broadest channel available for those looking to target consumers on the go. It also is good news for banks, retailers and other businesses that look to SMS as a way to expand their services and increase consumer stickiness – an outlet that won’t be available if users begin to drop their texting plans.

Traffic from carrier texting services will soon plateau and eventually fade away, of course, as network operators continue their slow devolution toward becoming dumb pipes (although there are ways carriers can stave off that fate with their SMS businesses, at least for a while). And the erosion of SMS revenues will come hand-in-hand with decreasing revenues from voice as cellular moves toward an IP-centric  world where everything that moves across the network is viewed as data. For at least the next few years, though, SMS will continue to deliver the lion’s share of our messages across mobile devices.