How to improve the customer service level of sales department

Suggestion: 1. Establish a customer database and insist on updating and improving information; 2. Classify customers, and different customers provide different levels of services; 3. Establish a customer information system, communicate feedback information in time, and use all possible means: such as telephone, email, collecting short messages, postcards, notifying customers of major holidays and company factory celebrations, inviting some customers to participate in activities and sending souvenirs!