What should you think about if you are purely going to sell your product online?
If the internet is your only channel to market you need to be very sure of what consumer need is going to drive your business model. Proven business models for selling products include clearance of branded items at low prices, so-called "long-tail" product ranges whereby rare items that are inefficient to stock in physical retail formats are sold and convenience replenishment items like sports supplements and children's nappies.
What is the advantage of a bricks and mortar store?
Physical stores provide customers with a "five-senses" experience. Sales of many product categories are assisted touch, smell, and taste - all senses that are not supported in an on-line experience. Many products also need to be tried physically to build trust - for example building confidence in the consistent fit of apparel.