My favorite ESP today
November 03, 2025

My favorite ESP today

Sue Cho | TrustRadius Reviewer
Score 10 out of 10
Vetted Review
Verified User

Overall Satisfaction with Customer.io

We use Customer.io as our ESP and CRM platform, for batched emails as well as automated user journeys including emails, in-app messaging and push notifications. We pass all of our user attributes and events seamlessly via Segment. Customer.io powers all of our Lifecycle initiatives to convert registered to trial, trial to paid and subscriber retention.

Pros

  • Email building + showcasing metrics (human opens vs bot opens)
  • Multi-channel support, continuously improving and adding new channels.
  • Pricing is very fair for all the features that are given.

Cons

  • Customer.io needs to be more known! I don't know why they don't come up as a direct competitor to Iterable and Braze.
  • Their new Design Studio drag + drop tool could be improved with further customization.
  • Reports aren't the strongest - I use Amplitude to do all my Customer.io reporting.
  • Increase in referrals shared via in-app messaging campaign.
  • Increases in key trial activities that contribute to paid conversion.
  • Encouraging users to take the "next best action"
Everything was pretty intuitive to use if you've used an ESP before. The only thing that was confusing is Campaigns vs Newsletters - some of their naming conventions aren't straightforward. But their docs, support and AI agents are all super solid.
There are so many ways to seamlessly connect all your tech together so the data stays consistent. I like their pricing model of charging per user vs data stored, like Iterable and Braze do. I also think their marketing is so good and the content they put out are actually helpful, actionable and on trend.

Do you think Customer.io delivers good value for the price?

Yes

Are you happy with Customer.io's feature set?

Yes

Did Customer.io live up to sales and marketing promises?

I wasn't involved with the selection/purchase process

Did implementation of Customer.io go as expected?

I wasn't involved with the implementation phase

Would you buy Customer.io again?

Yes

Great for companies with a lot of user + event data and want to take a multi-channel approach. A smaller company with <250k users would probably suffice with a smaller ESP, unless the growth plan is to go at least 500k and up.

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