A text message sent by mobile phone is much quicker to send and receive than an e-mail; it happens in real time. For very urgent or important communications, texting can be useful, especially for business professionals who are out of the office or traveling.
When something is urgent, or you have a short message you want to deliver quickly, text messages are probably the most popular, aside from phone calls. E-mails are more for long messages, i.e. job applications, business inquiries etc.
Given that people tend to pay attention to text messages more than e-mails, since the text message system is more based on private conversations, whereas your e-mail gets flooded with spam advertisements.
