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.

Shopify is a commerce platform that allows anyone to set up an online store and sell their products. It's the go-to eCommerce platform for young direct-to-consumer brands. It's ease of use and setup is what's most attractive to merchants, but also the incredibly vast Shopify app store.

Gorgias is 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.

With Mailchimp you can send newsletters and automated emails. You can build your email list with form or import your known contacts. Mailchimp offers pre-designed email templates and a drag and drop email builder.

HubSpot is an award-winning inbound sales, marketing, service, and CRM platform, that helps businesses implement inbound in their businesses. It's used across all industries, but for eCommerce it's typically integrated with WooCommerce.