Another important factor to consider is logistics and fulfillment. When comparing Amazon vs. eBay, you need to take the shipping system of each platform into account.
On Amazon, you can outsource your logistics to
FBA (Fulfillment by Amazon), where Amazon handles all of your storage, packing, and shipping. This option offers tremendous convenience, especially during peak sales periods. If you're managing large volumes, FBA allows you to scale your business quickly without worrying about fulfillment, but this convenience also comes at a cost.
On eBay, you can either use prepaid shipping labels through eBay or manage shipping yourself. However, you’ll still need to store your products at your own location and handle shipping, which might not be as convenient, especially during high sales periods.
In this sense, Amazon offers more convenience, particularly for high-demand, popular products, but it can be costly.