Facebook Conversions Pixels are great tools not just to monitor website or mobile apps conversions – those can also be controlled through #Google Analytics after tagging URLs – but they are also one of the tools needed to optimise campaigns (e.g. cost per conversion) or to build Lookalike audiences (see image below) that tend to reduce your spending on Facebook advertising by creating target audiences made of users whose interests are similar to the ones of whoever has already reached a goal relevant to your business. On average I have noticed a conversion rate always higher than other generic audiences, sometimes even double.
To implement Facebook Conversion Pixels (FBCP) you have to create it for a particular Ads account activated in your site and populated with users info (it is said that you need at least 100 conversions to build a lookalike audience list). Once created it can be shared with other Ads Accounts and it can work for different Facebook Pages managed through the same Ads Accounts.
Google Tag Manager makes possible to add Conversion Pixels whenever and wherever you need, into any web page or mobile apps, depending on specific conditions. The Conversion Pixel has to be placed into the HEAD of your web page but, as you know, Google Tag Manager (GTM), has to be placed immediately after the opening BODY tag.
The question is: will Facebook Pixel works if implemented through a GTM Custom HTML tag?
The answer is yes! After implementing FBCP, you can check if it is working using the FB Pixel Helper, a free extension for Google Chrome.
NOTE – However, I have noticed that if “support for Document.Write” is not active for the HTML tag, the FB Pixel apparently takes longer to load – however, it still work – and the result is as follow: