What is an affiliate link? The one parameter that earns

An affiliate link is an ordinary link to a product page with one extra piece of text attached that says who sent the visitor. That is the whole idea. The page it opens is the same page anybody else would see, at the same price, with nothing added and nothing hidden — the only difference is a parameter in the address that Amazon reads on the way in and files against your account.

Everything else people say about affiliate links is either a consequence of that one parameter or a rule about where you are allowed to put it.

The parts of one

Read left to right, an Amazon affiliate link has three parts that matter and a good deal that does not.

• The store. amazon.com, amazon.co.uk, amazon.de and so on. This is not cosmetic and it is where most money is lost; more on that below.
• The product. /dp/ followed by a ten-character ASIN — Amazon’s identifier for one specific item, almost always beginning with B0. You can strip everything else out of a product URL and keep only this; the page still loads.
• The tag. ?tag=yourstore-20. This is the affiliate part. Remove it and you have an ordinary product link that earns nothing.

The value of the first part is that it is short enough to check by eye. A correct Amazon affiliate link is legible: you can read the store, recognise the product code, and see your own name in the tag. If you cannot see all three, something has gone wrong, and the sections below are the usual reasons.

The trailing digits in yourstore-20 are not yours to choose. Amazon appends them according to the marketplace the account belongs to, and they are the only part of the tag you never type. The store ID in front of them is the part you pick once and cannot rename afterwards.

Affiliate link, associate link, product link, affiliate code

Four names, one thing, and the reason people cannot find a straight answer is that they are searching for whichever name they happened to hear first.

What people call it	What it actually refers to
Affiliate link	The whole address, tag included. The common name across every network, not only Amazon.
Associate link	The same thing, in Amazon’s own vocabulary. Amazon’s programme is Associates, so its documentation says associate rather than affiliate.
Product link	Also the same thing. Amazon uses this phrase inside SiteStripe for a link to a single item, as opposed to a banner or a search result.
Affiliate code	Usually the tag alone — yourstore-20 — rather than the full address. Occasionally someone means a discount code, which is a different thing entirely and has nothing to do with affiliate programmes.
Tracking link	The full address again, named after what it does. Amazon separately uses tracking ID for the extra labels you can create to split your reporting.

There is no technical difference between any of them. If a guide tells you an associate link and an affiliate link behave differently, it is describing a distinction that does not exist.

How you get one

You need an approved Associates account first — there is a sales requirement with a clock on it, and links you publish before approval do not retroactively start earning. With an account, there are three ways to produce a link, and they differ mainly in how much they scale.

Method	Good for	Where it stops
SiteStripe, the bar across the top of Amazon when you are logged in as an Associate	One link at a time, correctly tagged, no setup	One marketplace, and one link per visit to the product page
Writing it yourself: store, /dp/, ASIN, ?tag=	Bulk work, spreadsheets, anything scripted	Nothing checks you. A typo in the tag is silent
A plugin that holds the tag and builds links as you write	A site with more than a handful of links	Depends entirely on which one; some only handle a single store

If you want one built now without installing anything, our link builder takes an ASIN and your store ID and returns the address for every marketplace at once. It runs in your browser and uploads nothing.

Putting the finished link into a page is a separate question with its own traps — the rel attribute, buttons, and where the disclosure has to sit. We wrote that up for WordPress specifically.

The four ways an affiliate link stops earning

This is the part worth reading twice, because every one of these produces a link that works — the page opens, the product is right, the reader buys — and pays you nothing. Nothing appears in your reports, because from Amazon’s side nothing went wrong.

1. The tag is missing

The commonest single error, and it usually happens the same way: you were looking at the product in your browser, so you copied the address out of the address bar. That address has no tag in it. It looks exactly like an affiliate link to anyone reading the page, and it is not one.

Check any link you are unsure about by looking for tag= in it. If it is not there, no amount of clicking will ever credit you.

2. The tag belongs to the wrong store

Amazon Associates is not one programme. It is run separately in each country, with its own account, its own agreement, its own rate card and its own tag. A tag issued on amazon.com earns on amazon.com. On amazon.co.uk or amazon.de it is simply ignored.

So a reader in Munich follows your American link, lands on the American store, sees the shipping estimate and leaves — or closes the tab, searches the product on their own Amazon, and buys it there with no tag attached. The sale happens without you.

This is the expensive one, because it is invisible. A missing tag you can spot by reading the link. A tag pointing at the wrong country looks perfectly correct. The only way to find out how much it costs you is to look at where your readers actually are — the audience check does that from your own analytics, and most people are surprised.

3. The link was shortened or cloaked into something unreadable

Amazon’s Operating Agreement objects to links whose destination is unclear. Half the affiliate world runs redirects through /go/ URLs, so the rule is worth stating precisely rather than as a blanket ban: the objection is to the reader not being able to tell where they are going, not to the redirect existing.

Amazon’s own shortener, amzn.to, is Amazon’s and carries no such problem: the domain is recognisably Amazon and the destination is not in doubt. A generic shortener that hides an Amazon destination behind an unrelated domain is the shape that causes trouble, and the trouble is not usually a warning — it is the account.

4. It was put somewhere links are not allowed

An affiliate link is only allowed on the properties you declared when you applied. Amazon’s agreement rules out email, PDFs, ebooks and anything offline, and those exclusions catch people who assume a link is a link.

The newsletter case is the one that costs most, because it feels obviously fine and is obviously not: link to your own article from the email, and let the article carry the affiliate link.

What happens after somebody clicks

Amazon reads the tag, sets a cookie, and credits the account it belongs to if a purchase follows inside the window. The window is short by the standards of other programmes and it is not a fixed period from the click in every case — adding an item to the cart changes it. We took the exact rule from Amazon’s own wording rather than paraphrasing it, because the paraphrases in circulation disagree with each other.

Two things surprise people. The reader does not have to buy the product you linked to — anything they buy in the window counts, at that category’s rate. And a later click on somebody else’s affiliate link replaces your tag with theirs.

The rules that travel with the link

Two obligations attach to an affiliate link wherever it appears, and neither is optional.

• Disclosure. Readers have to be told the link earns you money, in plain language, near the link rather than buried in a footer. Amazon requires it and so does the regulator in most countries. Amazon publishes wording you may use as-is.
• The rel attribute. Search engines expect sponsored or nofollow on paid or affiliate links. Adding it does not affect your commission and leaving it off is the kind of thing that is fine until it is not.

Neither costs anything. Both are the sort of thing that gets skipped on the first ten links and is tedious to retrofit across three hundred.

Common questions

Disclosure, since this is our own site: Doozly is an Amazon affiliate plugin. It builds tagged product boxes from an ASIN and rewrites outbound links to the marketplace closest to each reader, with the tag that earns there.