In addition, self-established logistics can ensure the accuracy and timeliness of supply, guarantee the quality of customer service, and maintain the long-term relationship between enterprises and customers. However, the investment required for self-built logistics is very large, and the scale required after completion is also large, so the cost can be greatly reduced. Otherwise, self - built logistics will not be profitable for a long time. Investment cost is big, time is long, have adverse effect to business flexibility. In addition, self-built huge logistics system, need to occupy a lot of liquidity. More importantly, self-established logistics needs strong logistics management ability, and employees need to have professional logistics management ability. Domestic suning suning lotte, gome online, are operating wholesale e-commerce sites.