There's really only 2 main ones in my opinion.
1. Value - You can't be just another seller in your niche, you have to be able to offer customers more value that your competitors. That doesn't mean you have to do something completely unique, it just means you have to do things better. Whether that's selling a superior product, making the ordering processes easier, offering superior customer support or service, have better product descriptions and images. The more of these you can excel in the better. If you go into a market where you can offer customers a lot more value than your competitors then you'll do well.
2. Traffic - There's no point providing value if you don't know how to get people to see what you're offering. Whether it be SEO, PPC, cold calling, door to door you need to have a solid plan to get customers to find what it is you're offering. Master and implement as many methods as is practical to get your products or services in people's faces.
1. Value - You can't be just another seller in your niche, you have to be able to offer customers more value that your competitors. That doesn't mean you have to do something completely unique, it just means you have to do things better. Whether that's selling a superior product, making the ordering processes easier, offering superior customer support or service, have better product descriptions and images. The more of these you can excel in the better. If you go into a market where you can offer customers a lot more value than your competitors then you'll do well.
2. Traffic - There's no point providing value if you don't know how to get people to see what you're offering. Whether it be SEO, PPC, cold calling, door to door you need to have a solid plan to get customers to find what it is you're offering. Master and implement as many methods as is practical to get your products or services in people's faces.