It is a short message sent to mobile phones. 2. The message lenght limit is 160 characters. 3. First SMS was sent on 3 December 1992 by the programmer Neil Papworth.  He was a Vodafone director in the UK.  The message was sent to Richard Jarvis, a Vodafone director in the UK. First SMS was sent at a Christmas office party. 4. The avarage open rate of SMS is close to 99%. 5. Most SMS are read within 15 minutes of receipt.