Affiliate Marketing Secrets

If I had a website and I had banners and links to the major brand stores.

This is kind if a speculative question but I’m curious what people think.
A few examples of niche could be something like a ‘tea’ or a skateboard store….
The one thing with online is it might take a bit more to attract customers versus a store and shipping costs could add a bit to orders as well but there still is potential to reach a bigger amount of people if the audience is there,
Which do you think might get more business in these kinds of stores online or retail?
Thanks

I use this question to challenge multi-level marketers, network marketers, and people who don’t know math, don’t know business.
My point is this : I have never heard of ONE product, that has the demand of millions and isn’t sold in stores.
First criteria is that the seller/manufacturer actually intends to sell it to millions, and not a niche, fad, short term small supply. If a product is in fact intended to be sold to a small audience, fine, they can’t then turn around and claim there is unlimited potential income.
Second criteria is that there is actual demand for the product, and people actually want it. The best test of this, as far as I am aware, is people asking for the product, not the other way around. Stores carry products because they believe there’s demand, stores are less likely to waste time risking to shelve, acquire, or ship products around if there isn’t a good chance it’ll sell.
If the two criteria are met, I have never ever seen a product that isn’t sold in stores. Because if there’s demand, there’s profit, and why wouldn’t any store want a piece of the profit if it was real?
Therefore, isn’t it fair to say that any product intended to be sold to millions and has the demand of millions, can always be found in stores, and any product that fails to be found in stores (including online stores, Amazon, eBay) has no demand, no profits?
(We are assuming it’s a legal product)
Can anybody help me find ONE exception to this rule? Is there any reason a product CAN be sold in stores, or wholesale, but seller DOESN’T WANT TO? I can’t believe that. I am more than happy to believe the stores don’t carry the item because there’s no demand, no profits.