The following aspects need to be considered:

1. Popular products: Douyin is a popular social media platform where users like to share popular products and trends. Therefore, Doudian supply chain needs to pay attention to popular products and trends to meet user needs.

2. Product quality: Product quality is one of the important factors for consumers to purchase goods. Doudian supply chain needs to select high-quality products to ensure consumer satisfaction and word of mouth.

3. Price competitiveness: Doudian supply chain needs to select reasonably priced products to remain competitive. At the same time, the supply chain needs to consider costs and profits to ensure the sustainability of the business.

4. Supply chain reliability: Doudian supply chain needs to select reliable suppliers to ensure a stable supply and timely delivery of products. The reputation and service quality of suppliers are also important factors in selecting suppliers.

5. Market demand: Doudian supply chain needs to understand market demand and trends to select products that meet market demand. At the same time, the supply chain needs to adjust the product portfolio in a timely manner to adapt to market changes.

In short, Doudian supply chain product selection needs to consider multiple factors comprehensively to select products that meet market demand, have reliable quality and reasonable prices.