Let's imagine that you're a YouTube star, called Davina Internet, with a following in the hundreds of thousands, if not millions. If Amazon accepted your invitation to join its program, you'd be able to set up a storefront at amazon.com/Shop/DavinaInternet. You'd then curate a list of products from Amazon's site that you recommended on your channel or otherwise think would be neat for other people to buy.
Of course, this does mean that there's yet another link between social media stars and the murky world of advertising. One of the way that many Instagrammers can make some serious bank is by recommending a product as if they used it. In fact, Kim Kardashian has had a few stern looks from the FTC and FDA for promoting products without disclosing that she was paid to do so.