Negative keywords are important to any PPC campaign as it can help filter unwanted traffic before a user even reaches your landing page. For instance, you are trying to attract people interested in shoes, but you don’t sell red shoes. By adding “red” as one of your negative keywords, you can be sure you are not spending money on clicks from people looking for red sparkly shoes so you have more funds available for those looking for brown loafers.
Google, Yahoo! and Bing allow you to add negative keywords into your account but they each approach it a little differently. Google provides the most options allowing you to specify Broad, Phrase or Exact match negative keywords. Negative keyword match types work a little differently than traditional search terms, so make sure you think through each negative before adding it into your account.
Negative Broad: if used correctly, this can filter out a lot of different variations. If a keyword is Negative Broad, then your ad will not show anytime the entire term is used within a search query. For example, if your negative is video game, your ad will not appear for someone searching for game video or video game deals. BUT know that this will not prevent ads from showing for variations of the word. That means that if you want to exclude both video game and video games (plural version) you need to add in BOTH as negative keywords. Also, Negative Broad match will not restrict ads from showing if someone searches on only one of the words. So if someone searches for board game you will still appear, as the word game on its own is not a negative.
Negative Phrase: this match type works similarly to traditional search terms in that it will exclude the phrase. A negative keyword is designated as phrase match when quotations are used around the phrase. If someone searches for only one of the terms in your phrase, your ad will still appear. For example, if your negative is “fiction novels” and someone searches for history novels, your ad will still appear. This also means that if additional words are used in the search query, such as fiction romance novels, your ad will still appear as fiction and novels are not next to each other in the search query.
Negative Exact: this match type will eliminate very little traffic as it only excludes searches for the exact term(s) in the order they are used. To designate a negative term as Negative Exact, include [ ] around the term. If someone uses any other terms in his or her search, your ads will still appear. For instance if your negative is [green sweater] and someone searches for ladies green sweater your ad will still appear as it does not match the negative term exactly.
The Google AdWords blog has put together this chart as a quick reference of the search queries that would be ruled out depending on your negative match type.
Yahoo! has a similar concept but it is referred to as Excluded Keywords instead of Negative Keywords. In Yahoo! you don’t have the same match type options, so keep in mind that what you add in as an excluded term is essentially a broad match keyword. There is a limit of 500 excluded keywords at the account level and each of the ad groups. You can also add in 1,250 excluded words at the campaign level if you choose.
Bing allows the addition of negative keywords at the campaign, ad group or keyword levels. Know that if you use multiple levels, the keyword-level negatives override those at the ad group and campaign levels and ad group negatives override those at the campaign level. As with Yahoo!, there are restrictions on the number of negatives that can be added in. At the campaign level, the negative keyword limit is 1,022 characters and you are required to place a comma between each keyword. This quickly reduces the number of keywords you can add in, so make sure you are choosing the keywords that will rule out the most traffic. Similar to Yahoo!, you are not able to designate match types so all keywords entered are again broad match.
If you haven’t added negative keywords into your account yet, a good place to start is by running a Search Query Report to review what users are searching on to get to your ads. This will get you started, but the report only shows information for those that have clicked on your ad. Don’t forget you also want to eliminate irrelevant traffic that may not have clicked yet so do a little research to see what other terms people might be using. Also, if you haven’t gone through your negative keyword list in a while, you might want to take some time to review what is currently in the account. As your business changes, negatives aren’t always updated so while terms might have made sense to exclude in the past, they may be relevant now.