Customer.io vs Substack

See how their public offers line up before you choose your own position. Prices stay in the currency, billing schedule, and charged unit each vendor publishes.

Customer.io

See full pricing history

USD · US · source: customer.io

Plan	Pricing	Charged by	Offer type
Essentials	USD 100 monthly Starts at $100/month billed monthly	Flat · per month	Standalone · Starting at
Premium Highlighted	USD 1000 / month with annual commitment Starts at $1,000/month billed yearly	Flat · per month	Standalone · Starting at

Substack

See full pricing history

USD · US · source: substack.com

Plan	Pricing	Charged by	Offer type
Free publication	Free Free to publish without paid subscriptions	Flat · per month	Standalone · Free
Paid publication	Substack retains 10% of paid subscription revenue, plus card fees Substack retains 10% of paid subscription revenue, plus card fees	Usage · percentage of subscription revenue	Standalone · Usage based

What each plan includes

Feature names follow each vendor’s own pricing page, so verify the wording before treating them as exact equivalents.

Customer.io

Essentials

Plan card Profiles: 5,000

Included
Plan card Emails: 1 million/month

Included
Plan card Visual workflow builder: Included

Premium

Plan card Unlimited workspaces: Included
Plan card Advanced governance: Included
Plan card Dedicated implementation support: Included

Substack

Free publication

Plan card Newsletter publishing: Included
Plan card Subscriber management: Included
Plan card Hosted publication website: Included

Paid publication

Plan card Writer revenue share: 90% before card fees

Included
Plan card Paid subscriptions: Included
Plan card Audience analytics: Included

How their prices changed

Each dated row shows the public prices observed when that vendor’s pricing page changed.

Customer.io

August 27, 2026 Source
- Essentials: USD 100 monthly
- Premium: USD 1000 / month with annual commitment

Substack

August 27, 2026 Source
- Free publication: Free
- Paid publication: Substack retains 10% of paid subscription revenue, plus card fees