How to retain consumer loyalty?

According to a recent survey by Harris Interactive in the USA, it seems easy: less than 3% of customers having a family plan leave the service. So mobile operators have early identified that such plans build subscriber loyalty and reduce churn. Success is there with over 40% of US mobile users saying they currently have a family plan. Are those plans so marvelous? Appealing and discounted conditions to subscribe, high value delivered, a single bill, are deciding factors to subscribe. That means that when the plan nears expiration, consumers shop for the best deal in the market and if a better family plan presents itself, the entire family will jump to the new provider. So, in the long run, family plan might not prove a winning strategy for providers, except always proposing the best offer, but with an impact on profitability.