About similar keywords across ad groups
Your ads are eligible to appear when one of your keywords matches someone’s search term on Google or on search partner sites. But it may be that you have multiple keywords, from different ad groups, that match a given search term. For example, you might have identical keywords in two or more ad groups. Or you might have similar keywords -- like plumber course in one ad group, and plumber training course in another -- and both could match the search term training course for plumber.
This article explains what happens when you have similar keywords that could match the same search term across different ad groups. You can also read more about what happens when you have similar keywords in the same ad group.
How a keyword is selected
If you have similar keywords that could match the same search term across different ad groups, the preferences below are used to determine which keyword is used to enter an ad into an auction. These are the same preferences used to select a keyword when you have similar keywords in the same ad group, but keep in mind that the process is more complex here. This is because different ad groups might have different ads, landing pages, and campaign settings. All of these differences can result in varying experiences for customers, and can result in different Quality Scores for similar keywords in different ad groups. This will impact how the preferences are applied below.
The preferences rank approximately in the following order.
A keyword that’s identical to the the search term
If a keyword is identical to the search term, this keyword is preferred for triggering an ad, regardless of the ad group it’s in.
ExampleLet's say the search term is plumber course. If one of your ad groups includes the broad match keyword plumber course, while another ad group includes the phrase match keyword plumber, then the broad match keyword will be preferred because it’s identical to the search term.
An exact match keyword when the keywords are identical
If you have multiple ad groups with identical keywords, the exact match keyword is preferred for triggering an ad.
ExampleLet's say the search term is local plumber. If one of your ad groups includes the broad match keyword local plumber, and another ad group includes the exact match keyword local plumber, then the exact match keyword is preferred.
The keyword that has the highest Ad Rank
When several ad groups contain keywords that match a search term, the keyword with the highest Ad Rank is preferred for triggering an ad.
ExampleLet's say someone searches for plumber training course and your ad groups include the keywords plumber course and plumber certification course.
Keyword Ad Rank plumber course 1.5 plumber certification course 1
In this example, plumber course will be preferred because it has a higher Ad Rank.
NoteIn rare cases, the keyword with the highest Ad Rank might seem to be less relevant to a particular search term than other eligible keywords. Because higher relevance is generally correlated with a higher Ad Rank, this should happen infrequently. Try running a search terms report to see instances in which the less relevant keyword triggers your ad. Then, add that search term as a negative keyword to the ad group that includes the less relevant keyword.
Exceptions to preferences
There are scenarios for which exceptions might be made and the preferences above might not apply.
A campaign is limited by budget
Let's say your campaigns are called "Clogged Sinks" and "Broken Water Heater." In your "Clogged Sinks" campaign, you have the exact match keyword plumber, and in your "Broken Water Heater" campaign, you have the broad match keyword plumber.
All else being equal, the exact match keyword in your "Clogged Sinks" campaign would trigger an ad when someone searched for the term plumber because it's the more restrictive match type. However, if your "Clogged Sinks" campaign were budget-restricted, then the exact match keyword in this campaign would sometimes be unable to trigger an ad. This means the broad match keyword in your "Broken Water Heater" campaign would trigger an ad instead.
There’s a cheaper keyword with a higher Quality Score and Ad Rank
Let's say someone searches for plumber tool and you have the keywords plumber tools and plumber tool with the following maximum cost-per-click (max CPC) bid, Quality Score, and Ad Rank:
|Keyword||Maximum CPC bid||Quality Score||Ad Rank|
Usually, the keyword plumber tool would be preferred because it matches the search term more closely than the keyword plumber tools. However, the keyword plumber tools is cheaper and has a higher Quality Score and a higher Ad Rank. Therefore, the keyword plumber tools will be used in this scenario.
There is an excessive number of matching keywords
Imagine that you copy an ad group 5,000 times, and so you now have 5,000 instances of the keyword plumber in your account. When a user searches for plumber, rather than process all 5,000 instances, we’ll reduce the number of matching keywords. Then, we'll use the preferences described above.