Klaviyo: Email Marketing & SMS

All the "influencers" recommend this app over everything else but I don't know why. My biggest complain is the lack of integration with existing products in your store! I've done all the right things but when I look up certain products. Nothing comes up! Honestly I can't see any of my products with or without searching. I'm guessing it has to do with not paying for it? That's my assumption. Will update my score if that aspect changes.