Statistics have it that there are as much cell phone users in the world as there are people in the world. A report from Wikipedia as at 2007 notes that about 74% of mobile cell phone users in the world are active users of SMS. In some countries, its up to 85%, and these statistics is only bound to have increased with passing years.
In view of this statistics, it is difficult to argue that text messaging has become a very important communication tool among people all-over the world today and rightly so. The ease of use, rapid outreach and instant delivery has made it the prime communication channel used today.
A brief history of how text messaging started and how it has grown might interest you.