Klaviyo

Mailchimp

Mailchimp is a widely used email marketing platform offering campaigns, automations, landing pages, and audience management, popular with small businesses. It has expanded into a broader marketing suite.

HubSpot

HubSpot is a customer platform combining CRM, marketing automation, sales pipeline management, and customer service tools into a single connected system. It is especially popular with small and mid-size businesses looking to consolidate multiple point solutions into one platform. Marketing Hub provides email campaigns, landing pages, and SEO tools, Sales Hub manages deal pipelines and sequences, and Service Hub handles support tickets and knowledge bases - all sharing the same underlying contact and company records so every team has a unified view of the customer. HubSpot's free CRM tier has been a major growth driver, letting companies start managing contacts and deals at no cost before upgrading to paid Hubs as their marketing, sales, or service needs grow more sophisticated.

ConvertKit

ConvertKit (now Kit) is an email marketing platform designed for creators — writers, YouTubers, podcasters — emphasizing simple automations, tagging, and monetization tools like paid newsletters. It favors plain-text, relationship-driven emails.

BillionMail

BillionMail is a cloud‑based email automation platform designed for marketing teams and businesses that need to send high‑volume, targeted campaigns. It combines powerful segmentation, dynamic content, and real‑time analytics to boost engagement and ROI. The service runs entirely in the browser, requiring no on‑premise installation, and offers dedicated email support to help teams launch and optimize their outreach quickly.