Upon pulling demographics for a general analysis overview of the internet I realized that Google’s information in Google Ad Planner is very much different than Quantcast’s information. I tend to believe Quantcast a bit more because of the simple fact that certain sites can be “quantified”. What that entails is a website adds some code to their site so Quantcast can track all of their traffic and demographic data.

To test my theory that Google isn’t giving proper stats I took the gender demographics of the top 100 sites in traffic that were quantified and compared them with Google Ad Planner stats. The problem with Google vs. Quantcast is that there are limited stats that both agree on. Gender and children in household are the only two that sync up as there are ONLY two options, male & female and yes & no respectively. Other stats like household income, age range, and even college attended don’t quite match up, as both sites have chosen different division points for stats.

As you can see below Quantcast’s directly measured stats for males are in blue while the Google Ad Planner comparison stats are in red:

In the following table you can see the difference in percentages between Quantcast and Google Ad Planner. In almost all instances Google Ad Planner is shy of the actual target. Google is only equal with Quantcast once and is off as much as 13 percent:

The bottom line is this: don’t rely on just one source for your analytics and statistics. Google may be a reliable name to many but unless they’re actually measuring data on the company’s behalf then they’re just guessing at best. If ever in doubt use the wisdom of the crowd. Choose many sources and take the average of all of them. It may not be the best solution (the best would be direct measurement) but when you have no other option finding out the hidden wisdom of the crowd may be your best bet.