Conversion Rates For Singular And Plural Keywords

Recently we wrote about the difference between singular and plural keywords in search engine optimisation and the effects on search engine results when using either version of a keyword (e.g. ‘chair’ or ‘chairs’). The conclusion was that figuring out which is best to optimise for is difficult, and so it’s usually best to go for both. This got me thinking about what kind of users will search for either type and if it will have an effect on a website’s goal conversions. Does either the singular or plural bring more traffic than the other? Is one more likely to lead to a sale than the other? Will someone searching for one spend more than someone searching for the other?

I decided to check website statistics across a number of sites that achieve a good number of sales and rank well. More importantly, rank well for both the single and plural versions of a keyword. The following is average data for the past 12 months from 2 websites in the electrical goods industry, for keywords that all rank in the top four in Google’s organic results (above the fold on most computers). Perhaps it’s a sign of our abilities in SEO, but there was enough analytics data to also include statistics for keywords with “’s” at the end of them:

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Traffic over the past year: 9000 unique visitors
Average transaction value: £800
Conversion rate: 0.23%
Per visit value: £1.54

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Traffic over the past year: 4000 unique visitors
Average transaction value: £600
Conversion rate: 0.34%
Per visit value: £1.77

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Traffic over the past year: 1500 unique visitors
Average transaction value: £450
Conversion rate: 0.19%
Per visit value: £0.85

Looking at these results, the first thing you may notice is how the singular version of the keyword tends to be the most searched, and this was generally the case across most of the keywords checked. Not too surprising was that the ’s version of the keywords were searched at much lower volumes.

Average transaction values follow a similar trend, though it is worth pointing out that there was much more variation in this across the different keywords.

Interestingly, conversion rates are generally higher for the plural versions of keywords, and it’s not immediately obvious why this would be the case. One theory could be that people searching for the singular version of the keyword have a particular model or make in mind which they’re not finding on our website, while people searching for the plural version are more open to the options available and choose from what our websites have to offer. Again, the ’s version was quite far behind in conversion rates.

The plural version comes out on top for per visit value too, although figures are much closer between the plural and singular versions. Taking into account the average traffic over the year too, it follows that the singular version has actually led higher levels of revenue than either of the other types of keyword.

Be aware that these figures are not necessarily the case for all keywords. This was only a relatively small sample, and in only one industry. It’s possible that the demographic of people searching for electrical goods have very different searching and buying habits than those searching for, say, beauty products.

It is interesting, however, that there are significant differences in results between the singular and plural keywords in our test. Ideally, broader tests need to be done to include keywords related to more industries but these initial results certainly lead me to believe that there is value in researching this kind of information for your own industry before committing to a search engine optimisation campaign.

Rik
SEO Programmer