Google Analytics accuracy is not infallible. There are multiple issues that impact its accuracy, including the software platform it’s operating from. That would not be a problem if the average website owner/user actually understood the real purpose of Google Analytics. Analytics is NOT designed to record website traffic statistics accurately. Google Analytics is less accurate, especially when compared directly against server log files. GA is instead designed and intended to monitor and analyse what people do when on the site. That’s why it’s called "Google Analytics" and not "Google Statistics"… Variations between Google Analytics and web server log files can vary from 10% to as much as 75%… That variation depends on the site architecture, any conflicting JavaScript code and sundry other variables! GA results are indicative rather than absolute and are best used to identify trends, assess poor-performing pages, monitor the effectiveness of Adwords advertising campaigns and track visitor behaviour on the site.
An SEO marketing company should be strictly honest with customers. GA should never be seen as an accurate way to measure website traffic. That’s NOT what it’s designed for. Despite that, there is endless discussion on this topic across the globe… "Why are you ambivalent about Google Analytics? "Trying to use Google Analytics to assess web site traffic is like using a screwdriver to undo a nut… And yes, you can keep doing it over and over again. However, the RESULT is ALWAYS going to be suboptimal! 1. How to use Google Analytics to Track Visitor Activities1.1. Where do they go internally? Which pages do they exit from? GA is a behavioural tool… It’s good at measuring conversion ratios. What percentage of people follow the traffic flow "funnel" you’ve visualised? How many end up doing whatever it is you’d like them to do? Regardless of whether that’s making a purchase, filling in a contact form or joining a mailing list, you’d like to know if things are getting worse or better…
You can edit a page and monitor the impact on conversions… You can alter your Unique Selling Proposition, or Call to Action, and measure the impact… The accuracy shortfall is because GA is running as a tack-on chunk of JavaScript code at the Top Source Media services or bottom of your pages. It then passes information to your Google account. It is therefore prone to both interference and error… Other JavaScript elements on the site, web server software and PHP coding may easily interfere with Google Analytics accuracy and performance… GATC. This prevents some traffic and users from being tracked. It leads to holes in the collected data. Privacy networks like Tor will mask the user’s actual location and present inaccurate geographical data. Some users do not have Javascript-enabled/capable browsers or turn this feature off. However, these limitations are considered small, affecting only a small percentage of visits. The largest potential impact on data accuracy comes from users deleting or blocking Google Analytics cookies.
Without cookies being set, GA cannot collect data. Any individual web user can block or delete cookies, resulting in the data loss of those visits for GA users. Website owners can encourage users not to disable cookies. For example by making visitors more comfortable using the site through posting a privacy policy. GA uses a page tagging technique to collect visitor information via a combination of JavaScript and cookies. It has limitations with websites browsed from mobile phones. This is due to the fact that only the latest phones are currently able to run JavaScript or set cookies (Smartphones and Top Source Media services PDAs). These limitations affect all on-site web analytics tools that collect on-site visitor data using page tags. That is, Top Source Media services the small piece of code (usually JavaScript) that acts as a beacon to collect visitor data. GA limits reports to 200,000 randomly sampled visits at the profile level for its calculations. While margins of error are indicated for the visits metric, margins of error are not provided for any other metrics in the GA reports.