What does Klaviyo do well? Klaviyo is a pretty good player in the same space as mailchimp. Mailchimp has a bit more backing which shows in the marketing, follow through, and the kind of programs they run. Klaviyo is a bit less expensive with a newer code stack.
What does Klaviyo not do well? It has a lot of potential, but there's a wide gap between what's accessible to do and something that's more complicated. There are things that aren't well explained in the portal for flows, or automated elements.
What do you wish you had known about Klaviyo before using? The partner program isn't as well put together as it looks like on the surface. Would like to see it a bit more organized. I have industry friends who don't get payouts or any documentation as to what they're being paid for, nor do we.
Have you used a competitor to Klaviyo? If so, how does it compare? Mailchimp - it's neck and neck, sometimes each is a bit better than the other. I see the potential with Klaviyo, but it's not quite 100% polished.