Why Facebook Ads Data Mismatches Google Analytics Data

Why Facebook Ads Data Mismatches Google Analytics Data

There are often data discrepancies between Facebook clicks and conversions data with that displayed in Google Analytics. In most cases, you might be seeing Facebook data as high than that of Google Analytics.  

While using both Analytics and Facebook for tracking ads performance, you always expect the same results across both tools. But unfortunately, we see a huge discrepancy in data between both tools.  

There are many factors that result in a change in data between both tools. In this article, we will look into how both tools measure conversions and what are the main reasons behind the huge data gap.

 

How both platforms attribute conversions?

The main reason that causes a huge data discrepancy is the way both tools attribute conversions. It is very important to understand this philosophy to be able to digest the data gap.

Google Analytics by default works on last click attribution model. Which means Google Analytics will attribute a conversion to the very last source a buyer landed to your website. For example, if a buyer saw your ad on Facebook and then later bought a product using Google search, Analytics will give credit to Google instead of Facebook.

While Facebook always credits itself a conversion if a buyer purchases a product after seeing or clicking a Facebook ad. By default, Facebook uses 1 day post view and 28 days post-click attribution. Which means, if a buyer sees an ad and later he purchases that product within 24 hours, Facebook will count that purchase no matter if the buyer clicked that ad or not. If the buyer clicked the ad and purchases the product in the next 28 days, Facebook will count the conversion.

Reasons for data discrepancies between Facebook Ads Data & Google Analytics

1. Cross-Device Tracking

Cross-device tracking means tracking the same user across multiple devices. By default, Google Analytics doesn’t track users across multiple devices. It assigns a unique client id to every new user that lands on your site. This id is used to identify new vs returning visitors.

If the same user visits your site from a new device, Google Analytics assigns a new client id to the same user instead of identifying him/her as a returning visitor. To track the same user across multiple devices, you will have to setup cross device tracking via user id.

On the other hand, Facebook easily tracks the same user across devices because most people are logged into Facebook from their phones as well as the web.

2. Verifying facebook conversion tracking

Facebook uses a JavaScript code for tracking conversions. For tracking a product purchase, the conversion code should be placed on the thank you page. If you have mistakenly placed this code somewhere else, then you won’t be able to track a conversion.

For example, if you have a lead generation Ad, the conversion code should run after a successful form submission. The reliable page to add the conversion code would be the thank you page. If you add the conversion code on the form submission page, it will run every time a user lands on the page and will result in inaccurate data.

The best way to set up Facebook conversion tracking is via Google Tag Manager. Anyone with a little knowledge of JavaScript can set up following the step by step guide.

By default, Facebook displays all conversions. To view each conversion data separately, open customize columns. Under conversions select website and then check the conversions for which you want to see the data. 

facebook conversions view

 

3. Verify Google Analytics Installation

Google Analytics tracks a website visitor using a JavaScript code snippet. It is recommended that you add this code in the head section of your page. This makes the analytics code to load before anything else happens on your site.

If you place this code somewhere in the body or footer, chances are you are missing out visitors who abandon your site before it fully loads. Hence, this can cause the Google Analytics data inaccurate.

4. Handling Internal Traffic

Google Analytics have filters to exclude internal traffic. You can use them to exclude hits coming from your own company. If anyone within your company clicks on your FB ads and lands on your site then Google Analytics will not track this click.

Additionally, if you are testing a product purchase or anything else you will still not be able to see data in analytics. While Facebook will still be reporting all about this and hence you can see analytics data less than that displayed in Facebook.

5. All Clicks vs Link Clicks

link clicks vs all clicks

You need to understand the phenomenon of clicks. Facebook displays two types of clicks. All clicks include likes and shares on your ads whereas link clicks refer to actual click on your ad that gets the visitor to your website.

If you compare all clicks with that displayed in Google Analytics, you will probably see all clicks being higher. The reason is that all clicks include likes, shares and also link clicks.

6. Facebook Clicks vs Google Analytics Sessions

Another very important concept you need to learn is the difference between Facebook clicks and Google Analytics sessions. When we talk about Facebook clicks, it is simply a click on an ad, and it will get counted every time a visitor clicks on your ad.

Google Analytics session is a quite different from clicks. A session starts when a visitor lands on your website. In some cases, it happens that a visitor clicks an FB ad, lands on your site and suddenly quit before anything loads on your site. In this case, Facebook will track a click but analytics session won’t start which results in less data in analytics.

The default session duration in Google Analytics is 30 minutes which means a session will expire if a visitor doesn’t interact with your website for 30 minutes.

A session contains actions a user takes on your website, it can be a link click, a pdf download or a product purchase. In a nutshell, if a user clicks multiple times on your Facebook ad within the 30 minutes session, it will be recorded as one in Google Analytics, however, Facebook counts every click.

7. JavaScript & Cookies for Google Analytics

Google Analytics records data when the JavaScript tracking code runs and identifies the user with cookies. In case a user turns off JavaScript running on their browser or clear cookies, Google Analytics will not be able to track and identify the visitor.

For tracking clicks on your ads, Facebook doesn’t depend on any JavaScript code. It will track all clicks on your ad. However, for conversion tracking, Facebook uses a JavaScript code snippet known as pixel. If the pixel code doesn’t load on visitor’s browser, it will not be able to track any conversion.

 

How to Reduce Data Discrepancy

Unfortunately, there is no such method to reduce the discrepancy. However, you can follow the following two methods.

A simple method you can follow to view accurate data is by looking at your server file logs. It displays data to a certain accuracy and can be used for making your business decisions.

To understand which channel was more involved in the conversion, multi-channel funnel reports can be helpful to look at. By default, Google Analytics include any interaction within the last 30 days to the conversion path but you can also change it to last 90 days.

multi-channel conversion visualizer

The report displayed in the above image is known as multi-channel conversion visualizer. It shows the percentage of total conversions by path, and include different channel combinations. You can study further about multi-channel funnel reports to better understand the channels that are involved in the conversion path.

 

Bonus: How to Compare Google Analytics & Facebook Data

You may have been viewing Google Analytics and Facebook data separately and it’s really a daunting process to compare reports when they are at different places. The best tool that we recommend to view and compare data is Google Data Studio.

It allows you to import data from multiple sources and build a report on the single screen. This way it will be easier for you to view data and hence a better way to compare data.

Note: If you are new to Data Studio, you can follow our step by step data studio guide for building an awesome report.

 

Conclusion

Facebook and Google Analytics both are different tools built for different purposes. Facebook’s concern is only with ads and whereas Google Analytics is built to track all your website traffic. Keeping the above factors in mind, there is always a chance of 5% discrepancy between both tools. However, more than 10% can make you worry about your data.

Hussain Mehmood

Hey I am Hussain Principal Analytics Consultant @ MarketLytics focusing on measurement strategy and analytics implementation. I started marketlytics in 2010 to turn my passion for understanding user behaviour into my day job. I use & extend google analytics, tag manager and kissmetrics everyday to deliver performance measurement & data driven insights.