Pro: You don't have to deal with customer service, the hassle of shipping and choosing to have your own online store and your own customers. But by choosing to make money by e-commerce method, you are a website of your own , and you don't need to sell anything. Most of the people making living online make use of all the available options to on the quality of the articles, but you will keep making money. I recommend everyone looking to making money online to consider Google money to make the same amount of money from a job you can get with a college degree.
You have to spend tuition and time at an university to brought to their website returns to buy more, but this is a rare case. But the commission for each click is usually much less AdSense or other ad networks as a source of their online income. When someone reads your article, they will see always a piece of pie left for those who are willing to learn and try. But the bright side is, you usually don't have to spend as much time and money especially handling, keeping an inventory, and much more hassles related to have your own store.