Computer hardware sells like hotcakes online. There are so many ways to trade and the target market is infinite. You may deal with local customers where they can pick up the product in-store or international where shipping is involved.
Merchants are not subject to the occasion when selling computer hardware. On the other hand, if you are selling computer related parts and items where demand for the products is greater during certain holidays such as Christmas (Ex. People buy "The Simpsons" as gifts to their friends), then you are likely to profit by focusing on such product.
Anyone can sell with a storefront, or by putting ads in online marketplaces and forums. If you build your own electronics ecommerce store because you are selling 100 items or so in your catalog, then you should also look into the other aspects of your ecommerce site such as shopping cart, web design, and payment processing or free credit card merchant account.
Are you going to be a reseller? Will you buy sell brand new or used items? A lot of free credit card merchant account providers can back you up in selling hardware online. They may provide not only free online storefront setup, but also good discount fees and low transaction rates. Others may even install you a free shopping cart. Most free credit card merchant account providers also do not ask for monthly minimum fees. However, if you're selling a large number of products, then you will have to consider other options since many free credit card merchant account providers have a monthly volume limitation.