What is DA and how will this link benefit my site?

Domain Authority (DA) is a grade or score (ranging from 0-100) that estimates how well a website will rank on Google and other search engines. A website with a high DA score is likely to rank higher in Search Engine Result Pages (SERPs). A link from Amazon can help to raise your site's DA score and hence increase your rankings, resulting in more search engine traffic.

I don't sell any products on Amazon?

This doesn't involve selling anything so you don't need to have a product. Your link will be posted on a dedicated page with no other outgoing backlinks. This is a very strong dofollow link back to your site.

Can I see a sample link?

Sure, here is an example of an existing link to give you an idea: https://www.amazon.com/Tsouaq-com-Evaluate-the-best-products/dp/B07S2QXHSV/

You can see the dofollow link under 'Developer Info', in the bottom-left (on desktop), as in this image: https://imgur.com/a/IejLeHR

Is this a one-off fee?

Yes. There are no weekly, monthly or yearly fees.

Is the link permanent?

As we aren't Amazon, all we can say is that we have been running this service now for over 3 years and achieved 100s of links for our customers. Not a single link has ever been taken down.