4 Usage. People may be heavy users, medium users, light users, ex-users or non-users. Finding out why people have become ex-users or non-users can be very useful for a company. Often, ex-users represent the most lucrative market since they are already familiar with the product. In recent years, customer winback has become of increasing importance to firms. What many marketers try to do is target heavy users and lure them away from competing firms. This is problematical, however, because there will undoubtedly be resistance from the competitor. A better tactic might be to encourage light users up to being medium users, and medium users to heavy users, while re-recruiting ex-users.