Klaviyo
Category Leader 2026Best for ecommerce brands that need catalog-driven flows and revenue attribution
Klaviyo is an ecommerce customer database that happens to send email. Deep Shopify integration, catalog-aware flows and per-flow revenue attribution make it the category standard for product sellers, at a price that rises fast with list size.
- Drag-and-drop email builder
- A/B testing
- Send-time optimization
- SMS marketing
Free plan
paid from $20/mo