Open an Online Store
Yes this can be done for free and you can make money. Amazon and Zazzle are just two places where you can be in business in just minutes. WePay is another great place to open your very own online store!
At Amazon, you simply build a free only store and act as a third party. You build the store, advertise it and let it do the rest.
At Zazzle, you can set up a free account, open a free store, design mugs, hats, t-shirts and more. Place them up for sell and advertise.