We work on Shopify - and without proper end-to-end analytics, it felt like we were flying blind. We decided to try First-Party Shopify Data - Shopify Attribution. This is probably the first solution that glues ad sources with real orders. It automatically pulls up UTM tags, links them to orders, and even lets you see which campaigns bring in money, not just views. By the way, everything is put in place quickly - without any extra code. So this is the best option, as far as I'm concerned.
Mitch Harisson