SamCart is a really slick provider for building checkout pages that convert. They take care of everything like building your checkout page, one-click up-sells, payments, and much more.
When someone makes a purchase in SamCart, you can Tag them in ConvertKit.
1. Add your API key
You'll need to add your ConvertKit API key into the SamCart integration settings page. You can find your API key by going to your account page inside ConvertKit.
2. Edit a product and select a Tag
Then edit a product in SamCart and go to the Integrations tab for that product. From there, select a Tag to be applied when the product is purchased or refunded. It's that easy.
NOTE: You will see an error in SamCart if you don't have any Tags in your account. Be sure to create at least one Tag before adding your API key.