Server side vs. Client side Tracking
Server-side tracking has numerous benefits. Improved tracking accuracy, faster page load, and data control are the most important. Considering that Safari and Firefox prevent third-party cookies and Chrome will phase out third-party cookies in 2024, it is highly recommended to add server-side tracking to your store.
There are two main downsides of server-side tracking: costs and complexity.
After implementing server-side tracking, clients will in most cases see an increase in their PPC campaigns results. According to a Google’s research article, Square has seen a 46% increase in reported conversions from Google Ads after implementing server-side tracking.
Both Facebook and Google, but also other platforms highly recommend their users start implementing server-side tracking. The reason being that it positively affects the accuracy of the collected data since Adblockers, tracking restrictions, iOS 14, etc. will have less or none impact on this technique. The two main reasons are: using a custom subdomain for server-side tracking that sets first-party cookies and replaces request domain, as well as advanced event matching based on user data.
Adblockers work in many different ways, and one approach is to stop tracking scripts by identifying the requesting domain. As an example, if using google analytics the blocker will identify that the requesting domain is google-analytics.com and block it.
By using servers side tracking the requesting domain will instead be the domain owned by you, hence making it hard for the Adblockers to detect that this is a GA request. As an example, you might be sending the request from tracking.yoursite.com which will not be a known domain within the blacklist of the Adblockers.
With the help of server side tracking, you can enrich data before sending. For example, you can track orders not collected by the tracker but available within your ecommerce system in Google Analytics or Facebook. This could be orders placed over the phone or orders being blocked for some of the earlier mentioned reasons. It may help you build custom audiences or get a full picture of where orders are coming from.
Another frequent use case of data enrichment is to combine multiple data sources before sending the data to the destination. It helps ensure that all sales data appear in GA, FB, or other analytics tools.
With the use of server side tracking you get the possibility to set first-party cookies that could live for two years. This should be compared to third-party cookies that are set, for example for GA on the domain https://www.google-analytics.com that will live for 1 or 7 days.
Regulations like GDPR, CCPA, or CSP, states that you should strictly control when you collect information about your site visitors and to whom you share it. It is forbidden to send any PII (personally identifiable information) to third-party vendors.
When implementing web tracking pixels, you are not in control of the data being collected at the site and how this data is being used by the receiver, for example Google or Facebook/Meta. Using server side tracking you regain this control and have the possibility to configure each vendor separately. By creating datasets like audiences or customer segments within Engage, instead on the receiver end, like for example Facebook, you are also in charge over how the data is being used.
It is not unusual that ecommerce stores are running with a handful of different third-part scripts all designed to collect data for each specific service. That will of course work, but most of the services require the same kind of information, hence running multiple scripts is just a waste of server resources. This will slow down the site resulting a lower organic position and worse user experience. The better approach would be to one server side data collecting service and then distribute the data to each destination using each vendor's defined API. This will not only speed up the page load, it will also secure that tracking data will be in sync across you IT-landscape.