Many times when your trying to sell in high yield markets such as electronics, everyone and their brother is doing it. The big guys already have the products at lower rates than what the small guys can buy them for at the start, or even if they source some products in bulk. When a small seller is buying 100 TV, well the big guys on Amazon are buying 1000's.
Guess who is going to get the lower rate? The big guys.
When we tried to get into some market places, we don't go after the most popular products. We think out of the box, I've always used this statement. Does the world need another "seller". If not, then move on.
Take ipod for example, they are super popular, but wait then it means everyone is going to be selling them. If you niche down, you can be fighting with fewer sellers, and increase your chances of making a profit.
Do a search for iPhone cases, look how many people are selling them. Lets say 10,000 people (not correct numbers, but it's an example). Now your selling against 10,000 people fighting for business.
Pick a big market, but niche down, so you have less people fighting for your sales. Once you niche down, niche down even more. iPhone Cases for example, niche down to pink cases. Then take it even more to pink hard cases.
Today, it's really the outside the box thinkers making it into the market place, and getting returns. I never thought we would sell soo many pens, but hey there is a market.
It's really the only way to do it these days less you have a lot of capital.