How Accurate are Alexa, Compete, DoubleClick and Google Trends? Back in January, SEOmoz did a test of free statistics services like Alexa, Compete, DoubleClick, and Google Trends. Their conclusion was that the visitor data provided by these services did not match their own analytics. Does that mean all of the data provided by these sites are rubbish? Not necessarily. We have relied on these tools for competitor research for ages, so we thought we would go beyond just the visitor data and look at other key pieces of information to see if they match up with Google Analytics data.