At Nature and Bloom, we use Klaviyo for email marketing combined with Optin Monster to capture new emails and increase our list size.
If you're in eCommerce, there is nothing better than Klaviyo. To put it simply, Klaviyo makes you money, whereas its competitors help you build an email list which you need to figure out how to monetize.
Klaviyo can segment your email list based on the broadest set of attributes compared to its competitors. Using a decision tree methodology, it allows you to send automated emails based on every conceivable action your customers have taken on-site or within a previous email. This deep level of segmentation enables you to take different approaches based on how engaged your subscribers are.
Aside from this, Klaviyo also allows you to do traditional email marketing, which isn't fully automated but also uses its segmentation technology in parallel to improve click-through rate and engagement.
It's also incredibly easy to use, with a plug and drop decision tree anyone can set up in a matter of minutes. As a result, by using Klaviyo, I have increased my email list by over 200% in the last 3 months, and more importantly, I can attribute over 15% of my total revenue to automated email marketing.
The only downside is that it's much more expensive than its competitors, and these costs can mount up quickly if you have a massive email list! Still, I believe it yields the largest ROI compared to its competitors, and I'm happy to pay the premium as it drives incredible results on autopilot.