We send 96 billion text messages every day in the UK but the very first, sent 25 years ago today, was pretty simple: "Merry Christmas."
"Spelt with the full words – not Xmas," says Neil Papworth, the British engineer who sent it, eschewing the abbreviations that would define the medium.
That first SMS (it stands for short message service) wasn't even sent on a mobile phone. Handsets could only receive messages, not send them, so Mr Papworth typed out the season's greetings on a computer.
"I don't know if they really thought it was going to be a big thing," Mr Papworth says.
It took a while for texting to catch on. SMS-capable phones were only just available in 1993, but as mobile phones became more popular, texting skyrocketed.
By 2007, we were sending 66 billion SMS messages a year in the UK; in 2012, we sent 151 billion.
The US was slower to catch on, mainly because mobile operators there charged more for texts and less for voice calls, and because of the popularity and availability of PC-to-PC instant messaging or IM.
And perhaps because they missed that initial adoption, Americans still don't add the customary 'x' at the end of a message.
The first SMS was "an incredibly important development in the history of mobile telephones", according to Elizabeth Bruton, curator of technology and engineering at the Science Museum in London. It was when phones, around for more than a century, moved beyond mere audio.
"For the very first time we have mobile telephones that were more than just literal mobile telephones, moving beyond voice communications to a new application of the mobile spectrum – to sending, literally, text messages.
"And we can see that continuation through to today when we have hundreds of thousands of applications on our smartphone. So SMS can be considered the first step towards the modern smartphone."
SMS changed norms of social interaction. Rather than calling someone – interrupting them and demanding their attention right that moment – it let people choose when to reply.
It pioneered one-to-many communication – you could send the same message to many different contacts.
When Twitter launched in July 2006, it borrowed SMS's 140 character limit.
But 2012 proved the peak for text messages, in terms of volume; they've been superseded by internet-based apps like WhatsApp, Facebook Messenger and iMessage.
In 2015, 30 billion messages were sent every day globally on WhatsApp, compared to 20 billion sent via SMS.
That also marked a more fundamental shift, away from an open standard which anyone could use (even if your operator charged you) to closed messaging systems controlled by technology giants.
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SMS still has a future, though, "because it works where very few data standards will work," Ms Bruton says. "You don't need Wi-Fi, you don't need 3G to be able to send a very basic text message."
Happy birthday SMS xx.