Marketo is an enterprise-level marketing automation and email marketing platform, while Klaviyo is a lightweight, easy-to-use, analytics-driven platform for e-commerce marketers. Marketo is more suitable for larger companies that need a very complex and powerful platform to manage their email marketing campaigns, lead nurturing, and tracking analytics. Klaviyo, on the other hand, is perfect for smaller online stores and is fairly straightforward to use. It is simple to set up and promises more personalized customer engagement. Marketo offers more sophisticated segmentation and reporting tools, as well as robust features like A/B testing and drip campaigns, while Klaviyos main focus is on email automations and targeted campaigns. Marketo also allows users to easily integrate with other systems and third-party applications, while Klaviyo mainly integrates with shopping carts and keeps its feature set limited to those needed by a typical e-commerce user.