Yes, you read the title of this post correctly. Keyword research data accuracy can be extremely difficult to gauge, even with access to the best keyword research tools. Today, I’ve been testing the output of our (internal) Google Adwords API tool.
Having the tool allows much faster automation of large keyword research projects for SEOgadget clients, but I’m still interested in the differences between the API data, the public legacy Google Adwords tool data and the new Google Keyword Tool data.
2009 Legacy Vs Beta Shootout
Last year we compared the legacy Google Keyword Tool to the newer, beta version. Back then there were some significant differences in the data and things haven’t changed all that much. In this test there’s such variation in the numbers that there’s no point trying to spin fancy correlative measures or any statistics whatsoever in this post. The charts speak for themselves, and you can take a look a the data by downloading it here.
The only important thing to remember is both the external tools give local and global search volume from the previous month. The API data provided in this spreadsheet is a monthly average (over 12 months) for the UK locally and globally.
Google UK Local Search Volume
Click to enlarge the chart – the difference in search volume is amazing.
Google Global Search Volume
Again, click to enlarge the chart – differences in search volume numbers are significant.
Which Tool is Best?
I’ve been feeling generally better about the reliability of the data from the API tool over the external tools. Much of that sense is based on an understanding that the data is averaged across the year – you’re far less likely to get tricked into making a decision based on a single, seasonally impacted value. Of course, the newer Adwords Keyword Tool allows you to export the seasonal (monthly) values too and in reality there probably is no “best” tool or approach. Good keyword research should take as much data into account as possible, including additional insights from Webmaster Tools and your clients paid search campaigns.
Keyword research is about common sense decision making with an awareness of the strengths and weaknesses of the data from your tools. Provided you can keep those strengths and weaknesses in mind and stay objective, you’re better off having the numbers than not at all. I think the topic of keyword research in SEO is so subjective that many SEM’s bring a difference of opinion on methodology.