The phenomenon that is the tablet computer has dominated the computer industry over the past 2 years. The Post-PC era is a common phrase used to describe where the industry is going and the sales figures that are issued every month confirm our current obsession with all things tablet.
However, the smartphone will always beat the tablet in terms of sales numbers, amount of time used and for most of the tasks we need every day. There is one issue with tablets that means they will never compete with phones- their size. You cannot carry a tablet everywhere and you cannot use it 24 hours a day like you can a phone.
For all of the limitations smartphones bring including smaller screens, slower data entry and compromises in matter performance, its size is exactly what makes it so successful. Wherever we go, we can always carry our phones and that will always be the case. Tablets will continue to be successful, but they will never (ever) compete with the phone.