Is a free tier a reliable signal that a platform is cheap to run at scale?

Not by itself. Klaviyo publishes a free tier but doesn't list a flat cheapest-paid price on Crail's data — its cost scales with contact/message volume, which is the norm for this category. Treat the free tier as a way to test the product, not as a preview of your bill at real send volume.

Does having an MCP server actually matter for choosing a marketing automation tool today?

It matters if you're already using an AI agent or assistant to build or audit campaigns. Klaviyo and ActiveCampaign both publish an official MCP server on Crail's data; Customer.io, HubSpot Marketing Hub, Braze, and Marketo Engage do not, which means any agent-driven workflow with those tools has to go through their standard API instead.

Choosing a marketing automation platform

The real split in this category isn't email vs. SMS features — it's whether you can sign up and start sending today, or whether the platform you want requires a sales call before you see a price.

Marketing automation pricing rarely maps to a single number on a pricing page — it moves with your contact list size and message volume, and the platforms in this category split sharply on how much friction stands between you and a working account. Some let you sign up and send a campaign the same day; others require a sales conversation before you learn what anything costs.

Self-serve vs. sales-led is the first fork

Klaviyo, Customer.io, and ActiveCampaign are all buyable without a sales call, per Crail’s data — you can evaluate and start on your own timeline. HubSpot Marketing Hub has a free tier and a published entry price ($20/month) but still lists a sales call as required to buy, which typically means self-serve works for smaller plans while anything beyond that routes through sales. Braze and Marketo Engage are sales-call-only with no published cheapest price at all. If you want to compare real pricing before committing time to a demo, that already narrows the field.

Where each platform’s strength actually shows up

Ecommerce-specific fit. Klaviyo’s data emphasizes deep Shopify/BigCommerce integration — relevant specifically if your marketing automation is anchored to an online store, less relevant otherwise.

Data-driven, developer-friendly automation. Customer.io is positioned as self-serve customer engagement for teams that want to build automation off their own event data, rather than a pre-packaged suite.

All-in-one suite breadth. HubSpot Marketing Hub and ActiveCampaign both bundle marketing automation with CRM/sales features — useful if you want one system rather than integrating a standalone automation tool with a separate CRM.

Enterprise cross-channel orchestration. Braze and Marketo Engage are built for larger, cross-channel (push, in-app, ABM) programs, and are priced and sold accordingly — quote-only, no self-serve entry point.

Compliance and agent-readiness aren’t identical

Every vendor Crail tracks in this category carries GDPR at minimum, and most carry SOC 2. Where they diverge is agent-readiness: Klaviyo (83) and Customer.io (70) score highest on Crail’s scale, while Marketo Engage sits at 20 — the lowest in the category. If you plan to have an AI agent build, QA, or monitor your campaigns, that gap is worth weighing alongside the feature list.

Where to start

Compare current pricing, compliance certifications, and agent-readiness scores for every vendor on the Marketing Automation category page, or see a head-to-head breakdown in Klaviyo vs Customer.io.