People around the world are starting to use two or more mobile phone numbers on a regular basis for a variety of reasons (and using a variety of techniques, including special 2-in-1 SIM cards).
Another motivation to have more than one number is for the user to control how one is contacted and contactable. Naturally users typically have a strategy on handing out the right number to the right person for future contactability. Our research participants most commonly report separating private and business contacts by having separate numbers. Being able to switch one number completely offline is a way of switching the mental mode, such as “I am turning my work phone off as I am not working anymore”. Small business owners and those who deal with a large number of people can identify the type of contacts easily by differentiating which phone number they use. One Chinese electronic shop owner gave out one of his mobile phone number for his best customers, ensuring that he is always reachable for them. The ease of having another mobile phone number also provides the exclusive communication channel for some, like those in early or secret relationships.