Amazon.com has been around for a while now and has become without a doubt, the worlds leading e-Commerce retailer. Where Google is to internet searching, Amazon is to shopping. For a while, eBay was the only place to sell things online, and I personally sold a lot on eBay. eBay is great, but it requires a lot of work on your part: sourcing, listing, shipping, customer support etc.
Amazon created something called Fulfillment By Amazon which works a lot like eBay, but in my opinion, is MUCH better.
Fulfillment by Amazon: Fulfillment by Amazon or as referred to generally as allows anybody to list their items on Amazon. What makes FBA so awesome is Amazon will handle everything for you: they will list the products, they will handle payments, they will ship the products and they will handle all of the customer service for you. Win-Win-Win.
Think about it this way: You find great products to sell which have a high profit margin for you. You prepare a shipment of all of your products you are selling and put it in a bax with prepaid shipping and send it to Amazon. Amazon receives your inventory and when it is sold, collects the payment and ships the product to the buyer. Amazon handles all of the customer support, you never have to deal with anything for service, and finally, Amazon sends you your money.
Amazon wins as they sell the product and make money, your customer wins as they get the product they wanted and you win profiting from the sale.