He wasn't selling products on amazon, just linking to products that were already for sale and getting paid by Amazon for the traffic. See "product links" on this page: https://affiliate-program.amazon.com/gp/associates/join/land...
If you are not from the US, these things are not easy to obtain.
And last I checked they wouldn't even allow me to buy Amazon PPC advertising without these things either!
I then repeated this process in 2008 to incorporate, opened the business account and raised money (and put them on the account).
Now I'm living in the US, on a work visa, having no degree.
Guys, US is a fantastic country for anyone who actually _wants_ something. Put some creativity here and there and it works flawlessly. I laugh when I talk to US citizens (or read them online) who go on endless whining on how police state this country has become, how much burden you have to put up with to open the business, how the school system is in the toilet, etc, etc. They just don't know what they're talking about. Any US system could be ridiculed and laughed upon, and sometimes it deserves it. But it's fucking efficient.
Go open the debit card, bank account, business, whatever in, lets say France (I love this country, I've been there like 30 times and it's never enough). If you succeed you can come back to the US and apply for National Interest Waiver for being a person with extraordinary abilities in science AND arts AND business. Haha.