Amazon’s initial marketing plan was to sell to a specific product (books) to a specific group of people (the early internet adopters). There is a lot to learn about this because Amazon decided to sell to a small niche. As a matter of fact, it was a niche product to a niche audience.
This is the model that Facebook adapted too. Their first niche audience was students, then other universities in the US, then universities in other countries, before the general public.
Once Amazon mastered that audience and the mechanism which made it work, they added more products and a larger group. Amazon did not start like many supermarkets do, selling many products to the general public.
Sadly most startups still struggle with selling their initial product idea to a niche audience. Instead, they want to reach the whole world immediately.
See the Amazon story by Boomy Tokan
Reach a niche audience first!