The LA Times ran a fabulous article yesterday about why text messages only allow 160 characters for their messages.
The short answer is that the guy working on SMS (short message service) technology in the mid-80’s had to figure out a succinct way to communicate due to limited available bandwidth at the time. This had to be standardized across multiple cellular phone systems. They settled on 160 characters after reviewing postcard notes and Telex messages (popular “back in the day”).
The reason Twitter is only 140 characters is that they leave 20 characters for someone’s name to be added to the message.
Very interesting article. Check out the whole thing here.