Why are Google's keyword planner average monthly search estimates always so low?

Question

The Avg. monthly searches metric should reflect the average the number of searches for the term over a 12-month period (source).

But the returned average is quite often too low to really be accurate. For example when I go to Google's keyword planner and enter a moderately popular search term such as cron expression generator the result indicates that the average monthly search volume lies somewhere between 1K to 10K per month.

But when I Google the same term and then look at the average monthly visits of the first few websites on similarweb.com, the numbers just don't add up. For instance the website crontab.guru, a popular cron expression generator, gets about 605K monthly average visits according to similarweb. I can imagine that a good amount of those visits come from people who first searched for 'cron expression generator' on Google. Other cron generator websites also have a lot more monthly visits then 1K to 10K.

Also trends.google.com shows that the trend score for cron expression generator is actually quite high (region was set to worldwide and period to 12 months). So why does keyword planner return such a low estimate for this keyword group? How should the average monthly search estimate be interpreted?

Answer 1

The average monthly searches reported by keyword planner looks pretty much inline with what you see from Google trends. Google trends is showing maybe 75 searches per day. Multiplying that by 30 days in a month you get just over 2000 monthly searches for the term. That is squarely in the range that you say keyword planner is reporting.

Maybe you are confused by the phrase "over a 12-month period" and you are interpreting that as "average yearly traffic" rather than "average monthly traffic." Another way of defining what "average monthly searches" means would be: "Look at data from the last 12 months, how many searches the term received per-month." The reason that the 12-month period is in there at all is because Google wants to account for seasonal variability. Some search phrases (like holiday or back-to-school related phrases) get almost all their traffic in a single month, and Google averages that spike out across the whole year rather than just reporting what happened last month.

Your assumption that sites get a significant percent of their visits from a single three word search phrase isn't likely to be true. Brand names and single word search phrases sometimes drive a decent amount of search traffic if you rank #1 for them. However, two and three word search phrases are getting into the "long tail" territory. Sites usually rank for dozens or even hundreds of related two and three word phrases. There are many related search phrases in this case:

• cron expression
• cron generator
• generate cron
• generate cron expression
• cron format
• cron helper
• cron calculator
• ...