Etsy has an affiliate marketing program. I applied for it and unfortunately was declined. I wanted to sell a jeep fire pit on another website.
Here is what the fire pit looked like. Cool, eh?

Some Etsy items have a great sense of humour, something I look to sell at my store which focuses on weird, wonderful and amazing items.
A couple of funny products are:

and

I found many, many good products on Etsy that I would love to sell.
So, I applied as an affiliate. I went to https://www.etsy.com/affiliates and clicked on the Learn More button. This took me to https://ui.awin.com/merchant-profile/6939, which is a page by Awin that has Esty Canada on the left-hand side.
I clicked on “Sign Up and Join Program” and answered their many questions.
For some reason, most affiliate program applications ask many questions. They want to know how you intend to market to customers, what websites you are going to sell on, etc. They are fairly straightforward to answer.
Some affiliate programs charge a fee. Usually, this is a nominal fee. I cannot remember, but I think Awin charged me $5 to apply, and it would be applied to something or other that would eventually make things even. I cannot remember.
Charging a small fee keeps out non-serious people and prevents people from abusing the application process by applying thousands of times.
Then I have to wait a few days. Then I got an email from Awin.
Unfortunately, I was rejected. My site was not the type of site they wanted to partner with.
They want to partner with original content sites about personalized experiences with Etsy products.
If that is the type of website you have, and you want to promote Etsy products, apply to join their affiliate program!
Here are a number of books to help you start an Etsy business.
Here is a book on how to start an Etsy business and an affiliate business. I just found it, so I have to read it to find out if it is for setting up an Etsy affiliate business.