Selling on eBay can be a good business, but success depends on a variety of factors.

Here are some of the factors that affect sales performance on eBay:

1. Product selection: Choose products that have market demand and low competition. Analyze market trends and search for popular keywords to understand which products are popular.

2. Pricing strategy: Reasonable pricing is crucial. Study the pricing strategies of competitors and ensure that your prices are competitive. At the same time, consider profit margins and expenses.

3. Product descriptions and pictures: Create detailed and accurate product descriptions and provide high-quality pictures. This will help attract potential buyers and increase their willingness to buy.

4. Logistics and delivery: Provide fast and reliable logistics and delivery services. Ensure on-time delivery and provide accurate tracking information.

5. Customer service: Provide excellent customer service, answer buyers' questions, and handle returns and refund requests. Good customer service can improve customer satisfaction and reputation.

6. Feedback and Reviews: Strive to get positive buyer feedback and reviews. A good reputation will help improve search rankings and attract more buyers.

7. Continuous Optimization: Regularly analyze sales data and market trends, and continuously optimize your products, pricing, and marketing strategies.

8. Comply with platform policies: Make sure to follow eBay's policies and regulations to avoid account restrictions or bans due to violations.

Although there are many challenges in selling on eBay, you can still succeed on eBay with adequate preparation, research, and hard work. The key is to understand the market, choose the right products, provide excellent customer service, and continuously adjust and optimize your strategies.