I doubt that the name Wilfrido Pareto will be familiar but you will know the Pareto Principle under another name, the 80/20 rule. The 19th century economist Wilfrido Pareto was the first to point out that the worlds wealth was split along 80/20 lines, with 80% of the wealth being in the hands of 20% of the world population and vice versa. It is surprising how that principle applies in life, have you noticed that in any given task 80% of the task is accomplished in 20% of the time?
So how does this relate to your eBay or Amazon activities, well you will find that 20% of your product range will produce 80% of the sales. This is why it is so important to be on the lookout for new products all the time. As soon as you have found a hot selling product you will have the market place to yourself for a few weeks (months if you are lucky). So it is important to really hammer the sale of a new product before others catch on to it and the market gets saturated by competitors. This also means weeding out the products that produce a very poor return. You never know, you may prove Wilfrido wrong.
See you soon
Rob