Customers have a life cycle like products. If marketers can understand customers, they will have better profitability. The stages are: Reach & Awareness – Customers become aware of the company, Acquisition - Here company can identify the specific prospect by collecting information such as name and address on them and entering it into the CRM database, Conversion – In this stage, a company converts a prospect into a customer which includes the initial sale, Retention – Here first time customers are converted into continuing customers , and Advocacy – this is the final step in the life cycle where regular customers  are converted into advocates for your company and its products. Read more at: http://it.toolbox.com/blogs/insidecrm/customer-lifecycle-and-crm-75251