What's the biggest complaint that you have about your cellphone at this very moment? Think really hard.
Was battery life your answer? If it wasn't, then it should be somewhere on your list. Having to charge your cellphone's battery every single day can be very annoying.
Having your phone die on you when you're on the go can leave you completely disconnected from the people who need you most. That's why I sell second-phone solutions like the Emergency Phone in my store.
Having a second phone on your person means that you can use your state-of-the-art smartphone without worrying about a dead battery ruining your day.