There are many things you can sell on the internet. I have a friend and he is a game reseller. He sell key Steam game and he has made a lot of money from his job. You can do that too if you want 
Can you please elaborate more on this scheme? I'm thinking of doing some business but can't find a good source of Steam games that I can resell for cheap price.
Have you thought about selling some exclusive or rare collections like baseball cards, classic watch. It doesn't comes from you can start by working as re seller from the real seller 
Perhaps there is an idea to sell cards in this way via the Internet and for crypto currency. In this way, one can earn very well on the Crypto currency and thereby spread the word about crypto currency to a large number of people. The demand and popularization of Bitcoin is also very important in our business.Selling cards specially collectors items is very profitable indeed. But I'm seeing a lot of fake cards lately. Just be sure that you are getting a genuine card before getting one. I know that this market is huge but its gonna be hard to penetrate if I'm not mistaken. I'm thinking of selling watches, maybe this could be a good idea to the OP.