Negative keywords are a useful feature of Google AdWords that allows you to drop some search queries from matching your keywords and ads. This allows you to restrict your AdWords ad impressions to a restricted and targeted audience, thus improving your Click thru rate (CTR) and the quality score of the keyword.
It is not required that you have any negative keywords in your campaign. If you can target the right audience for your campaign by using the positive keywords, by using the phrase and exact matches then it is much more ideal. I would consider using many negative keywords as an easy but cheap cop-out and not spending much time researching the keywords.
Having said that, sometimes it cannot be avoided and using a few negative keywords is not that bad. The feature exists for the reason that there are some cases where it is best and only way to eliminate some search queries, but you should use it judiciously and with care.
The negative keywords is very highly dependant on your specific campaign and keywords. Anybody who says it needs to be used across all your campaigns and that it is vital regardless of the keywords is often lying or just trying to get your attention. Just like the keywords, the negative keyword list should be built over time by analyzing your traffic and matching queries.
Some negative keywords might be obvious even before you have set up your keywords. Most of the times, this occurs when the same words refers to two different things and products. As an example, if you are selling apples, then you probably do not want to match against queries that are searching for Apple computers and iPods.
Many times these negative keywords will not be obvious and you might not become aware of them till later. There are many different ways to find negative keywords that are appropriate for your campaign. The best place to find them is by using Google Analytics or whichever analytics software that you use. There is also a report that you can generate with in the Google AdWords that can be used to find them.
In Google Analytics
You can see a list of all search queries that matched your campaign in Google Analytics.
- In Google Analytics web interface, click on Traffic Sources tab in the left side menu
- Click on Sources to open up the menu
- Click on Search, and then Paid
- In the menu just above the table, select Matched Search Query as the primary dimension.
To see the matched queries on a campaign basis,
- Click on Sources and then Campaigns
- Click on the desired campaign in the table
- In the menu just above the table, click on More to open the drop down menu
- Select Matched Search Query as the primary dimension
Even though you can see these queries in Analytics, it is better to use the AdWords UI instead as detailed below, as it gives much more information such as the CPC, CTR and cost of each of those queries as well.
In Google AdWords
You can see the list from with the AdWords web interface as well.
- In Google AdWords web interface, click on the Campaigns tab to open campaign management screen
- Click and select the desired Campaign
- Click on the Keywords tab in the top menu of the content screen
- Just above the keyword table, Click on the Details drop down button
- Select Search Terms : All from the drop down menu
This will show a list of all search queries that matched against your campaign and keywords. This has the added convenience of the ability to add the query as a negative keyword right from the table.
Scan through all the search queries that are listed in the table to find any queries that you think is not appropriate or is mismatched for your campaign. You will see queries that should not be matching as they are clearly searching for another product or service than the one you are advertising for. Identify the part of the query that is not appropriate for your campaign. This could be one word or one phrase or multiple words. Keep a list of these words that you identify in order to add them as negative keywords.
The web interface also provides you with the ability to select and add the query as a negative keywords right from the table.
Relevance or improper matching is just one of the factors that you can use to identify negative keywords. Sometimes specific queries may not be giving you the desired return on investment (ROI) even though they are relevant. Then you can use these queries as negative keywords so as to spend more of your budget on the keywords that are performing much better. Sorting queries based on cost or goal conversions will provide you to find top underperforming queries.
Be careful when isolating words from the search queries. You have to make sure that those words are not also part of the queries that you want to target.
Be as specific and use phrase match or exact matches when possible with keywords when it is not possible to identify the negative words correctly. If you have been careful and judicious in choosing the positive keywords, then you must not have a large number of negative keywords.
It is usually not essential to add every possible variation of the keywords as Google algorithms does a good job of matching the keywords and its variations. But when and if in doubt add it.