The ideal number of keywords that one can use in an account is a subject of debate. Well, then is there any ideal number as such?  For better control over your keywords, better CTRs and improved quality score, resulting in lowering down you CPC, PPC experts across have shared a minimum figure they are comfortable with.

Melissa Mackey in her post says:

I usually strive for no more than 15 keywords per ad group. But I also have ad groups with 50 keywords or more, and that’s fine too. It just depends.

Kirk Williams mentions in his post about ‘10 Common Google AdWords Mistakes‘:

The best rule of thumb is to use no more than 20 keywords per ad group. Sometimes you can get away with using a few more, but exceeding a 20 keyword limit is a sign that your ad copy isn’t matching the keyword being searched as closely as it could.

Brad Geddes had a different opinion to share in his post:

The number of keywords that belong in an ad group is based upon how many keywords your ad copy describes. It is better to have more specific ad copy than more general ad copy. There is no magic number.

And as per google, here is the current account limit for keywords usage:

With that huge number, you have a lot of space to add on keywords as many. But why should you restrict your ad groups to a limited no. of keywords? Why is it advisable to break down your ad groups to deal with similar and related keywords? Why have separate ad groups for a specific match type of keywords?

We discuss the reasons here:

When in doubt

While adding keywords to your ad group, you might come across keywords that you struggle allocating an ad group to. In such a case separate those keywords altogether.

Ad Copy Relevancy

The ad copy should apply to all the keywords in your ad group. It works vice-versa, control your keywords to be more relevant to your ad messaging or tighten up your ad copy to cover all keywords being bidded for.

Easy to judge your keywords

Having a small list of bidded keywords help you scan through its performance and makes your ad group organization simpler. You can do a check on which keywords are performing and which ones are not, and take relevant action towards it. For instance if a certain set of keywords have a high CTR then you might want to create a separate ad group for it and allocate more daily budget to it, or keywords with low search volume can be replaced etc.

Improved CTRs

As you have added more of relevant keywords to your ad group that meet the search query intent of user, you will gradually see your CTR improve. With a huge list of keywords sometimes the relevancy goes for a kill and dropping CTRs dilute the performance.

Results in improving your Quality Score 

With improved CTR and relevancy, the Quality Score will also see being improved, resulting in refining your ad position and lowering your CPCs. All these factors are interrelated with each other. If one of it is improved, it affects the other factors emanating from it.

Reduced Ad Spend Wastage 

Since your keywords would be relevant ones for which you wish to receive clicks, the ad spend allocated is justified. However, in case of a humongous list of keywords, you might end up fighting to find out where and how your budget is getting depleted. Some of the keywords might turn out to be irrelevant for your business and hence you might want to exclude them from being bidded for.

Reduces Audit Time

You don’t have to grill your time in scanning for relevant and irrelevant terms. The time gets saved in doing other tasks of more importance.

Less Variance

While Google itself suggests on using 10-20 keywords when creating a new ad group. You might think of it as a best practice to continue, adding similar/related terms that stick with the theme of the ad group or excluding the terms that turns out to be low performing.

Mobile performance

If a keyword is performing better on mobile then you can create a separate ad group for it, where mobile bidding could be enhanced for the performing keyword(s)

Now that you know the reasons, how can you go about limiting the number of keywords in your ad group:

• You can create your ad groups basis a certain theme such as targeting a specific product, term etc.
• You can disintegrate your existing ad groups by finding similar/ related keywords and clubbing them under one ad group
• You can organize your ad groups basis keyword match types such as create an ad group with broad match keywords to find search terms you can bid on and add them in a separate ad group as exact match type
• For more finer control over your keywords you can opt to use Single Keywords per Ad Group, a break-free from the cluttered arrangement of keywords.

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