How long should a keyword be? It’s a basic question but one that has been getting under my skin for a few days now so I thought I should really take a look at it.

The Data
To complete this analysis, I looked at a huge data set, from a wide variety of accounts so that I was looking at the broadest picture I possibly could.
I then applied a few criteria to my data in order to rationalize my assessment and to improve the relevancy of my findings:

• Only look at the search term length, not the keyword length
• The data from lead generation accounts, not eCommerce
• Conversion data is call and email only, nothing else is included

Analysis
Once I had my data in Excel, I used a rather basic =countif() function mixed with a pivot table to get the data below. It shows the performance of over 450K search terms in an extremely basic format. This is because we are looking at just the core metrics here in order to gain a wider understanding of the subject, rather than digging deep to extrapolate a single key learning. This assessment is from the macro level, not the micro.

Learnings
As an experienced account manager (10+ years), I can’t really say that the results blew my mind. But it was interesting to see some certain trends emerge:

• The highest conversion rate from a keyword of any significance came from single keyword search terms
• The best CPA from a keyword of any significance came from single keyword search terms
• 3-word search terms have a higher CTR than 2-word search terms (actually just over double)
• 2-word search terms have a higher CVR than 3-word search terms
• The CTR of the search term trends up the more words there are in the string
• The CVR of the search term trends down the more words there are in the string
• Because of this, the CPA trends up the longer a search term is

Insights

• If you are running a search campaign with the intention of driving traffic then longer tail keywords are the order of the day
• For better conversion volumes at lower costs, you will need to have shorter search terms

Conclusion
The keyword length cannot be used strategically, as each account is blatantly different and has different needs and requirements.
This information can be used generally however when planning a campaign and mapping out its build.
Is it a campaign that will use Head Terms and Generics to pull in a large volume of traffic that can then be used to create remarketing audiences? Then use longer keywords and search terms.
Do you have a limited budget and need to drive as many leads as possible for a local service provider? Then maybe build a part of your campaign to have single keywords and test their performance.

Please feel free to contact the author if you have any questions about this process, or would like some advice on your Google Ads keyword selection.