Klaviyo is the best in class email marketing solution for eCommerce. It's powerful because it connects to your store, and you can create awesome customer segments based on past purchasing behaviors, customer preferences, and even future predictions of spending.

Recharge is the leading Shopify subscription solution for online businesses. It makes it easy to transform one-time products into subscription options.

Gorgias is one of the most popular helpdesks for D2C brands. It centralizes all your support tickets in one place and enriches them with lots of extra context about a buyer's profile. Through Gorgias, you can connect directly to your eCommerce store and edit orders, modify subscriptions, and refund payments without leaving your helpdesk.