Choosing Generic vs Specific Niche
A niche is a specialized part of the market where you should dominate sale and market share. For example, if you like pets then pet collar can be your specific market niche.
If you think pet accessories is your niche then you are being very general and can lose focus. Identifying your niche must start with specific item and then you must start working your way up till general items.
For example, sell dog collars until you dominate sales and market share then start offering dog clothes. After selling dog clothes for a while until you dominate sales and market share then start offering cat litter box so on and so forth. Keeping focus on specific item and gradually start selling generic item is the perfect plan.