Match Facebook pixel pageviews with Offline Event set?

Question

I would like to use offline conversion data to build a custom audience that I can match against visitors to my site. I am currently trying to do this by:

1. Using the Facebook pixel (fbevents.js) to track users, passing extern_id with our unique user ID during the init call and then tracking pageviews like so:

   fbq('init', '1234567890', {extern_id: UNIQUE_USER_ID});
   fbq('track', 'PageView');
   

2. Later uploading offline event data with the associated extern_id of people that have made purchases

But Facebook is giving me a 0% record match rate for the offline event set (I have ~150,000 pageviews and a couple thousand purchases, if that matters). Has anybody succeeded in matching only on extern_id, or does Facebook require more user data?

Answer 1

You should be passing external_id instead of extern_id in the fbq init event.

fbq('init', '1234567890', {extern_id: UNIQUE_USER_ID}); // Incorrect
fbq('init', '1234567890', {external_id: UNIQUE_USER_ID}); // Correct

You can check the doc here: https://developers.facebook.com/docs/facebook-pixel/advanced/advanced-matching

Answer 2

I spent hours on this and from what I can gather, the offline events only work in conjunction with Facebook ads. So, your uploaded data is matched only against ads in your account and not the Facebook pixel.