Without network providers, phones are incomplete. Without phones, people are incomplete. So, there is a strong bond between phones, phone users and network providers. One can select the network provider as per need and desire. Even once the contract period ends with the network provider, users can turn to other network. But to stay connected with the same can benefit more than turning to other network. Users mostly move to other network mainly for lucrative gifts and offers. And if the same benefits can be get with the older network, then moving to another is of no use. This is something what we can call is ' Mobile phone upgrade '. Existing users matter a lot for network service rather than new ones. They would be highly benefited if they can stop their existing users to go. Network provider (eg T-Mobile, Vodafone, Orange, O2, 3G, Virgin etc) offers cheap discount price, a new handset without any cost etc., to convince the user. As a result, users get the same benefit from their service provider for which they are moving to others. Between the user and the network provider, the contract period expansion gets exchanged with free devices and discount offers.