SNS – Social Networking Service – it means social media in Japan, but as far as I know, it’s not a common use in the worldwide. It might be confuse.
Not in Japan, but in US and UK, SMS – Short Message Service – was very big.
But in Japan, SMS only worked on the same network when we were using “Galapagos Phone”.
DoCoMo users couldn’t send messages to au users, but in other countries, they worked on every network and they are much cheaper.
But also “Galapagos Phones” were pretty good at emails, but the other country’s phones were not good at internet, they are good at calling and SMS.
So, everybody used SMS all time, and SMS was a very common phrase.
Then, after smartphones suddenly we could use email well and like WhatsApp came up. If we are talking about SNS in other countries, they would be confuse and might think “Oh, really? Japanese people still use SMS? Why not use WhatsApp or something?” 😛