PPC can be expensive. Negative keywords are a critical tool for reducing costs without damaging outcomes. They allow you to prevent ads from appearing for search queries that you have identified to be irrelevant or a low priority. The trick is identifying the right search terms to add to your negative keyword list.
Here, we’re going to explain how to go about identifying good negative keywords for your listings and how you can use negative keywords to reduce wasted ad spend and improve ROAS/adjust ACOS. Ultimately, we are going to explain how to go beyond negative keywords to deploy exact match PPC bids on Amazon. Let’s get started!
Step 1: The basics of negative keywords
You can’t run before you walk. If you already understand the basics of negative keywords, skip to step number two. But to make sure we are all on the same page — there are a few things worth covering.
What are negative keywords?
Negative keywords are exactly what they sound like — they are the opposite of keywords. Rather than selecting words/search terms you want to bid on for PPC ad placements (“positive keywords”), they are keywords that you highlight to avoid making bids on. If a negative keyword or phrase appears in the user search criteria, your ad doesn't show up.
How to put negative keywords into your Amazon campaign?
You can add new negative keywords in Seller Central by navigating to “Campaign Manager” in the “Advertising” tab:
Then, by selecting negative keywords, you can simply start to input negative keyword information at campaign or ad group level.
With that out of the way, it’s time to get started mastering negative keyword selection and campaign management.
Step 2: Broad match vs phrase match vs exact match
Keywords on Amazon operate in three different categories. Two of which function for negative keywords, and one of which is only available for positive keywords. These categories are:
- Exact match: Relates to search queries that exactly match the seed keyword, along with the plural variant. For example, a negative keyword of “kitchen knife” would restrict your ad from appearing in search queries for “kitchen knife” and “kitchen knives”. However, it would not impact search queries like “Japanese kitchen knife”, or “kitchen knife set”, or “knives for kitchen”.
- Phrase match: Relates to search queries that are close to the seed term, but more broadly applied than exact match. Word order is kept intact, and only close variations are included. In this example, “Japanese kitchen knife” and “kitchen knife set” would get captured in phrase match, but “knives for kitchen” would not — and neither would a synonym like “chef knife”.
- Broad match: This includes search queries that are related to the seed term, including synonyms and other wide-ranging options. Broad match settings cannot be applied to negative keywords, and are only a positive keyword option. But for the sake of illustration, a positive broad match term like “kitchen knife” would include synonyms like “chef knife” or “bread knife”, as well as completely different products like “toy kitchen knife”, “knife block” or “knife sharpener”.
Note: For phrase match and exact match, both “negative” and “positive” keywords operate the same way. A positive exact match keyword bid will put your ad up for action in the exact same way that a negative exact match keyword will restrict your ad from appearing. As we will get to, one of the best use cases for negative keywords is to selectively limit your positive “broad match” and “phrase match” PPC campaigns with exact match negative keywords.
How to use this information
The different match types for negative keywords allow you to engage with negative keyword selection more flexibly. “Exact match” is probably the best choice for both advanced and beginner users.
Exact match allows you to add negative keywords without risk of unintended consequences. For example, adding “kitchen knife sharpener” as a negative keyword for your kitchen knife ASIN could actually exclude that listing from appearing for the term “kitchen knife” or “sharp kitchen knife” if applied using phrase match.
Phrase match terms are helpful for excluding entire categories. For example, you might add the term ‘toy’ to your kitchen knife ad to exclude all kitchen toy sets. However, phrase match should be used cautiously, and you should make sure to reassess your campaign closely after applying these filters.
Step 3: Campaign level vs ad group level negative keywords
Negative keywords can be applied in two different ways: to entire campaigns or to specific ad groups. This allows you to more effectively control your negative keywords and segment how they are deployed.
Let's say you sell two lines of sneakers. One line has no pink sneakers, while the other does. In this instance, you would want to exclude the phrase "pink tennis shoes" from triggering the ads for the sneakers without a pink option. But you would want to retain ad bids for that term for shoes that are pink.
By placing these different product lines within different ad groups, you can apply different negative keywords to each, while keeping them within the same ad campaign for reporting purposes. Equally, you can set negative keywords that apply to both products simultaneously on a campaign level.
How to use this information
Your ability to flexibly engage with negative keywords will depend on how granular you make your ad group construction. The more you segment your campaigns into ad groups, the more targeted you can make your negative keyword selection. Ideally, you should consider creating single-product ad groups — providing you with optimal control over both positive and negative keywords.
Step 3: Find the right negative keywords
Finding the right negative keywords is the real advanced trick to making the most out of this PPC option. There are two main ways to do this.
- To start with, you can simply think about common irrelevant crossover. For example, “running shoes”, if you’re bidding on the keyword “shoe” for a fancy pair of leather brogues. This is not very scientific, but should be your first strategy.
- The systematic way to do this is to create experimental broad match positive keyword campaigns, and then analyze the search terms you actually appear in. This will not only provide you with real information about irrelevant terms, it allows you to dig into performance analysis and shave off underperforming and over-priced keywords.
It’s also worth noting that different analytics tools, as well as some of the Amazon Brand Analytics reports, can help you refine this keyword search, as well as provide context on how valuable these keywords are to your campaign. Check out our free eBook on Mastering Amazon Brand Analytics for more details.
Refining your broad match campaigns
Using negative keywords to refine your broad match campaigns is not only a great way to identify good negative keywords, it’s the primary use case for the application of negative keywords. By creating a broad match campaign, your ads will start to list for a wide range of terms.
Start by looking through that list and identifying irrelevant outliers. Add those one at a time to your negative keyword list using exact match.
Next, dive into the metrics. As a guide, there are three things to watch out for that indicate a good candidate for negative keyword selection:
- Low CTR non-converters: These keywords aren’t helping you win sales. If people aren’t clicking on your ad, it’s an indication that it’s irrelevant.
- High-click non-converters: The average conversion rate expected from Amazon ads is just under 10%. Industry specifics matter, so keep that in mind. However, if you have an ad with over 30 or 40 clicks and no conversions — it might be deadweight. If this is happening for every keyword, you need to investigate your product page, shipping rates and reviews. But if it’s just one word, there is likely a relevancy or audience problem.
- High-spend low-converters: This is the most subjective metric, and ultimately relates to your ad budget. But all keywords consistently in the top price bracket warrant extra scrutiny. If you aren’t getting enough conversions, consider removing or limiting your exposure to that term. It will help you keep your expenditures low.
With all of this said, there is a lot of variability. For example, if the keyword is important for ToF awareness reasons, or you are consciously targeting competitor branded searches, these factors will change the criteria for what makes a good/bad negative keyword.
Step 4: Stop your own ads competing against each other
Negative keywords also help you prevent your own PPC bids from competing against each other. For example, if you have a range of smartphone cases, you could use negative keywords to prioritize the cases you are most interested in selling for search terms like “smartphone case” while relegating other cases to more niche terms like “blue smartphone case”.
This strategy is less commonly deployed than using negative keywords to optimize broad match campaigns. However, it’s a lot simpler to execute. You simply need to identify these core terms by analyzing your product catalog, looking for crossover and then determining which products are more important to your business. Factors like impact on customer lifetime value and strategic business priorities can help you make the right choices.
Step 5: Move your broad match bids to exact match bids
Negative keywords are only really necessary to reduce the waste that is inherent to broad match and phrase match bidding strategies. But this is a sloppy shortcut to the real desired outcome — targeting bidding on only relevant and high-value keywords.
Your real goal with negative keywords should be to facilitate a move away from using negative keywords altogether — transforming all of your campaigns into exact match bids. Exact match bidding allows you to control your bid price and modifiers, optimize your exposure to the best terms, and ensure the capitalization of low-cost/high-converting terms.
How to use this information
The process of creating exact match bids on a product-specific level is time-consuming, which is the main reason it’s not always done. However, you should constantly be moving products towards this outcome. To do this, you effectively undertake the same processes required to identify good negative keywords in the first place — you analyze the keywords you are ranking for in broad match campaigns. To do this, you effectively want to look for the exact reverse of what we described in step 4:
- High CTR and high-converting terms
- High-click high-converting terms
- Low-cost high-converting terms
Terms that you identify as high-value terms should be removed from your broad match campaign entirely. That means adding that term to the negative keyword list for the broad match campaign, and then starting a new campaign for that term using exact match bidding.
Over time, you will slowly build up a catalog of exact match campaigns. In this eventual outcome, the main role of negative keywords is to exclude these exact match campaigns from your ‘exploratory’ broad match that you will want to keep running (potentially on a reduced budget) to keep looking for new terms.
We have an article specifically about this process of search term optimisation if you want more advice on how to manage and control these exact match campaigns.