Before starting a business, one needs to do market research, and find and unmet market need; an unmet need "customers" have that you can fill in exchange for money.
In "affiliate marketing" business, you start a website, blog or whatever, provide useful content and pre-sell affiliate products.
In a lot of "affiliate marketing courses" they just say "pick a niche with a lot of products", and contain a lot of lessons on how to build a website, write an article, outsource etc. etc.
But before one start a website, blog or a "squeeze page" to build an affiliate business, how does one move forward, step by step, research the market to find an unmet market need?
I mean how can I do research and find an unmet market need before starting my affiliate business?