Match type controls how closely a shopper's search term must match the keyword you bid on before your ad is eligible to show. Amazon Sponsored Products and Sponsored Brands use three: broad match, where the search must contain all the words of the keyword in any order, plus synonyms, related terms and variants; phrase match, where the search must contain the keyword's words in the same order, with words allowed before or after; and exact match, where the search must be the keyword itself or a close variant such as a plural or common misspelling.
Why it matters
Match type is the trade-off between reach and control. Broad match finds queries you did not know about and gathers the most data, but it also spends on the least relevant traffic. Exact match spends only on the query you chose, so its bid, budget and placement can be tuned for that one term, but it discovers nothing. Phrase sits between the two.
Match type also affects the price of a click. The same keyword in exact match often costs more per click than in broad because more advertisers are competing on the precise term, yet it converts better, so the cost per sale is usually lower.
What moves it
- Amazon's broad-match behavior, which has loosened over time to include more semantic variants, so broad campaigns need more negatives than they once did.
- Campaign structure. Mixing match types in one ad group hides which type is producing results.
- Bid separation. Broad bids should usually be lower than exact bids for the same keyword, because broad clicks convert less.
How we use it
We run each keyword through a ladder. Automatic and broad campaigns discover search terms at lower bids. A term that converts is moved into a phrase or exact campaign with its own bid and budget and negated at source. That gives control of cost and rank on every keyword that has proven it sells, while the discovery layer keeps finding the next one.