In this video, I show the complete Reddit conversion tracking setup for a Spiffy (SP) checkout page using Google Tag Manager—both browser-side pixel and server-side Reddit Conversion API. Most marketers get stuck because Spiffy is a custom checkout, so the normal “just install the pixel” method doesn’t give clean purchase attribution. I start from the Spiffy integration area, where you add your GTM container ID and activate the data layer, then I verify the purchase event in Tag Assistant to make sure the event is actually firing correctly. After that, I build the key GTM variables you need for Reddit: Reddit conversion ID, Reddit transaction ID, and user data like email (for me, email is the most important for Reddit matching). I pull currency and other purchase details from the data layer, and I configure the Reddit Purchase tag with pixel ID, access token, first-party cookies, and advanced matching. Then I send the required parameters from browser to server using the purchase data tag (from Stepi/Spiffy flow), and in server-side GTM I fire the Reddit Conversion API tag with access token and test ID from Event Testing. Finally, I confirm in Reddit Events Overview that both browser and server events are receiving properly—so your Reddit Ads optimization becomes more reliable and accurate.