Customer.io vs. Email on Acid

Talking from the perspective of a marketer at a SaaS with average. 50K email subscribers, Customer IO has been an excellent tool for us. Our requirements include sending users newsletters, marketing emails, and transactional emails, running lead-nurturing campaigns, and more. For a comprehensive use case like ours, CustomerIO is great. While it also has a learning curve, when you have such requirements, it’s worth it. I don’t think CustomerIO is the best fit if you have basic requirements like only weekly newsletter emails.

Incentivized

Suited: Pre-deployment QA and rendering validation: If your audience uses a diverse mix of email clients and devices (e.g., corporate Outlook users, gmail users on mobile, etc.) Email on Acid ensures consistency across all of them. Less appropriate: If your organization only sends basic text-based emails or uses template with minimal HTML customization, then Email on Acid might not be appropriate.

Incentivized

• Managing users, attributes and events. You are easily able to modify any user, based on their ID, and add or remove attributes, assign events to them. That makes it very easy to segment later and to assign them to several campaigns based on behavior. Just a warning: this integration isn't so easy (at least it wasn't for us).
• Creating workflows of campaigns is very easy. You can quickly create behavioral campaigns based on attributes, segments and add elements to the workflow. You can send an email, then wait, then send another, then exit the campaign if they converted, etc. The workflow is easy to configure and very powerful for automation.
• We don't use many email templates (we make them in MJML) but it's very easy to add senders, to change templates and in general to test designs.
• Deliverability works very well, at least for us. It sends emails pretty fast and without issues.
• Exporting is very quick and easy. Importing wasn't a feature until recently, but it works well too.
• Seeing activity it's also useful. In general, logs are awesome (be it of a customer, of activity on the site, email sends, etc.).
• We don't use environments, but it might be very useful for a bigger company.

Incentivized

• Email Spam Testing
• Email Code Editing
• Email Previews Across Multiple Providers

Incentivized

• Price is quite expensive for Premium or once you get into high volumes of contacts.
• Depending on how you'll use it, it may require some help from developers to set up.
• Despite the support being great, you have to email them, there's not chat feature.

• Limites Reporting and Analytics
• It a little slow when it comes to Rendering email clients
• The user interface is not so friendly

Incentivized

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.

Incentivized

I'd rate Email on Acid a 7 out of 10 for overall usability. It is intuitive, reliable, and greatly enhances the QA process for email campaigns, though there's still some room for improvement in speed and report flexibility. For example: the previews sometimes take longer during peek hours, especially for complex or image-heavy emails

Incentivized

My experience with their support team has always been great. Very quick to respond, have an online chat, and are very helpful. They helped me resolve any issues I've had every time in a professional and knowledgeable manner. We've now switched to another tool, and I can't even compare the service level we get there to customer.io

Incentivized

Customer.io was really the first pure, full-featured drip email program on the market and as far as I know, it's still the simplest and best overall for that specific function. SendGrid has also added drip campaign features, but I would seriously evaluate Customer.io against any other drip email provider because they really have all the key elements you need to make it work.

Incentivized

Email On Acid is very similar to Litmus, but perhaps slightly more reliable. I have used both extensively, and prefer Email On Acid.

Incentivized

• Positive impact on the sales side. I'm not sure about the specific ROI (you have to include the designer and the time it takes to set up) but you certainly get back the investment in a few months, once you are able to scale your email marketing.
• Customer experience is way better by having more segmented, contextual and accurate messages sent to them.
• Integration is costly and it will take several days or weeks to be fully achieved. Expect to invest some money on this.

Incentivized

• Ability to send over 1000 previews spanning across 90 email clients.
• Saves a lot of time getting emails out the door.

Incentivized