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You may miss the term “product”, as any business involves the exchange of a valuable product or service against money. I did not forget that. But in the beginning this will only slow you down.
But there are plenty of high quality products out there, which you can sell. You do not need to pay a dime for the right to sell them, and you can get nice commissions of 50% and more for selling them.
For this reason, if you start an internet business, you do not need to spend resources for developing and testing a product. In fact, you should not. It takes time and money to develop, test and tweak a product, before it can be a hot seller. And you need skills to do that. You will acquire many of these skills, while selling top products for a commission.
There is only one exception of this rule: If you have already an offline business, and you decide to extend your reach by going online, you can do this with your existing product or service.