指商品售出后，其生产厂家或销售单位对用户提供的保养退换、零部件供应、技术指导、故障维修等相关的服务性工作after-sales service

• 北京市质量跟踪广播电视工业公司加强售后服务。

  Quality tracking companies in Beijing in the broadcasting and television industry are improving after-sales services.

• 企业以良好的售后服务在消费者中赢得信誉。

  A company gains credibility among consumers by providing good after-sales services.