Customer IO

Automate powerful behavioral messages for web & mobile apps

★★★★★ 4.6/5
FactScore™ 64.7
VS

Success.ai

Supercharge your growth with AI-powered cold emails!

★★★★★ 5.0/5
FactScore™ 101.3

Updated February 2026

Customer IO Success.ai
Rating 4.6★ 5.0★
Reviews 24 105
Pros 10 14
FactScore™ 64.7 101.3

FactScore™ Comparison

FactScore™ weighs both quality (rating) and popularity (reviews) for a fairer ranking than stars alone.

64.7
Customer IO FactScore™
👑
101.3
Success.ai FactScore™
★ Success.ai wins on FactScore™

Pros & Cons

Only in Customer IO — Pros

Behavioral messaging Personalized communication Automation capabilities Free startup plan Segmentation User engagement Customer support Email builder Multi-channel messaging Workflow customization

Both tools — Pros

Only in Success.ai — Pros

14-day free trial User-friendly interface Unlimited warm-up feature Extensive lead database AI-powered email writer Excellent customer support Unlimited email accounts No credit card required for trial Cost-effective Advanced analytics Seamless CRM integration AI-driven analytics Campaign scheduling Cross-device tracking

Only in Customer IO — Cons

Complex interface Email editor issues Inflexible journeys Limited CMS features Slow UI

Both tools — Cons

Only in Success.ai — Cons

Details

Customer IO Success.ai
Categories Email marketing, Marketing automation platforms, Customer loyalty platforms Email marketing, Lead generation software
Platforms Web Web
Became Popular January 29, 2014 November 5, 2023
Website customer.io success.ai

Who Should Pick Which?

Choose Customer IO if...

  • Behavioral messaging
  • Personalized communication
  • Automation capabilities

Choose Success.ai if...

  • 14-day free trial
  • User-friendly interface
  • Unlimited warm-up feature

With a FactScore™ of 64.7 vs 101.3, Success.ai leads in community reception. Customer IO uniquely offers Behavioral messaging and Personalized communication, while Success.ai stands out for 14-day free trial and User-friendly interface.

3

What Users Say

Customer IO

V
Vova Jan 14, 2025
★★★★★

We made the switch to Customer.io after trying out Loops and Userlist, and it’s been a great decision. It’s powerful enough to handle all our SaaS communication needs, yet still easy to use. It wor...

D
Danielle May 13, 2025
★★★★★

Our new email campaign provider with a user-friendly interface, clear visual logic for campaign triggers, and lots of customization. The level of flexibility has encouraged us to be more creative a...

A
Ali Dec 29, 2024
★★★★★

Customer IO stands out for its powerful automation capabilities and behavioral messaging tools. It allows us to create highly personalized communication workflows, improving engagement and retentio...

Success.ai

A
Andrew Nov 6, 2023
★★★★★

Success.ai has streamlined our outreach strategy, providing us with the means to connect with professionals efficiently. Its user-friendly approach and the support available round the clock have re...

A
Amber Nov 6, 2023
★★★★★

Success.ai is an essential part of our marketing strategy, with its AI-powered features, extensive lead database, and user-friendly approach. It's been a game-changer, helping us consistently conne...

A
Andrew Nov 6, 2023
★★★★★

We've experienced remarkable results with Success.ai, making it an essential tool in our marketing arsenal. The platform's focus on meaningful connections and user support adds even more value to o...

Frequently Asked Questions

Which is better, Customer IO or Success.ai?

Based on FactScore™, Success.ai leads with a score of 101.3 vs 64.7. Success.ai has a higher rating of 5.0★ compared to 4.6★.

What are the pros of Customer IO compared to Success.ai?

Customer IO uniquely offers: Behavioral messaging, Personalized communication, Automation capabilities, Free startup plan, Segmentation.

What are the pros of Success.ai compared to Customer IO?

Success.ai uniquely offers: 14-day free trial, User-friendly interface, Unlimited warm-up feature, Extensive lead database, AI-powered email writer.

Is Customer IO better rated than Success.ai?

Customer IO is rated 4.6★ from 24 reviews. Success.ai is rated 5.0★ from 105 reviews.

What is the FactScore™ of Customer IO and Success.ai?

FactScore™ weighs rating and review volume together. Customer IO scores 64.7 and Success.ai scores 101.3.

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