Negative keywords allow advertisers to be less conservative with their keyword strategy, using more broad match keywords, while still ensuring that their ads are not triggered by irrelevant or less valuable searches. For example, let’s say you’re an optometrist who sells eyeglasses. In this case, you may want to add negative keywords for search terms like “wine glasses” and “drinking glasses.”
There is a lot of confusion around negative keywords, so I will defer to the Google support documentation to clarify as much as possible:
Negative Keywords
Negative keywords won’t match to close variants or other expansions. For example, if you exclude the negative broad match keyword flowers, ads won’t be eligible to serve when a user searches red flowers, but can serve if a user searches for red flower.
If you’re using Display or Video campaigns, negative keywords can help you avoid targeting unrelated sites or videos, but keep in mind that negative keywords work differently for Display and Video campaigns than they do for search. Depending on the other keywords or targeting methods in your ad group, some places where your ad appears may occasionally contain excluded terms. For Display and Video ads, a maximum of 5,000 negative keywords is considered. You can also avoid targeting unrelated sites or videos by implementing site category options and content exclusions.
Types of Negative Keywords
For search campaigns, you can use broad match, phrase match, or exact match negative keywords. However, these negative match types work differently than their positive counterparts. The main difference is that you’ll need to add synonyms, singular or plural versions, misspellings, and other close variations if you want to exclude them.
For Display campaigns, a set of negative keywords will be excluded as an exact topic. Ads won’t show on a page even if the exact keywords or phrases are not on the page explicitly, but the topic of the content is strongly related to the excluded set of negative keywords.
For example, a set of negative keywords like “women’s pants” would block bidding on a page with content about women’s jeans, even if the exact phrase “women’s pants” did not appear on the page. However, we would not generalize beyond the concept of women’s pants to other kinds of women’s bottoms (i.e., skirts) or men’s slacks. This is different from how we would treat a positive keyword—for example, shoes—which we would also match to a broader category like footwear.
Symbols in Negative Keywords
You can use three symbols, ampersands (&), accent marks (á), and asterisks (*) in your negative keywords. Negative keywords with accent marks are considered two different negative keywords, like sidewalk cafe and sidewalk café. Similarly, “socks & shoes” is different from “socks and shoes”.
Here are some of the symbols that our system doesn’t recognize:
Ignored symbols: You can add periods (.) to your negative keywords, but these will be ignored. That means the keywords Fifth Ave. and Fifth Ave, for example, are considered identical negative keywords. If you add pluses (+) to your negative keywords they will usually be ignored—for example blue+car; however in some cases if a + is at the end of a word (for example C++) it will not be ignored.
Invalid symbols: You’ll see an error message if you add negative keywords that contain certain symbols. Some of the symbols that can’t be used in your negative keywords are: , ! @ % ^ () = {} ; ~ ` <> ? \ |.
Site and search operators: The “site:” operator will be removed from your negative keywords. That means if you add the negative keyword [site:www.example.com dark chocolate], it’ll be considered the same as [dark chocolate]. Search operators will also be ignored. For example, if you add the search operator “OR” to the negative keyword dark chocolate, like “OR dark chocolate,” the “OR” command will be ignored, and your negative keyword will be just dark chocolate.
Other search operators: Adding a minus (–) operator to the front of a keyword will cause this keyword to be ignored for negative keyword matching. For example, if you have a negative keyword “dark -chocolate”, it’ll be considered the same as just “dark”.
Keep in Mind
Choose your negative keywords carefully. If you use too many negative keywords, your ads might reach fewer customers.
Negative keywords do not match to close variants so your ad might still show on searches or pages that contain close variations of your negative keyword terms.
There’s No Negative Broad Match Modifier Match Type
Your ad might still show when someone searches for a phrase that’s longer than sixteen words, and your negative keyword follows that sixteenth word.
