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How Clearbit Personalizes Emails with Customer.io (and Achieves a 49% Open Rate)

Clearbit builds a brilliant and extensive suite of API products. Exciting use-case ideas abound. Just a sampling: sales reps can get a lead’s company size from a single email, marketers can enrich lead and customer data to better segment their emails, and developers can integrate Clearbit with their own software to show rich profiles.

Having multiple products, use-cases, and audiences means that Clearbit has a lot of explaining to do. Their challenge: guide different types of users through custom onboarding experiences for multiple products. Clearbit has to get founders, salespeople, marketers, developers, and other professionals to all understand, adopt, and make the best use of their platform.

The solution, naturally, involves the clever use of data. Using their own Clearbit-enriched data, they segment their audiences and personalize content to tailor their lifecycle messages in Customer.io, delivering only the most vital and relevant information.

The result: a hyper-personalized email strategy that achieved an overall open rate of 49%. Here’s how they did it:

Segment free trialers by role

People who sign up for a free trial are usually newbies, who don’t yet know how a product can best serve them. Recognizing that their various buyer personas require different information to get started, the Clearbit team knew they needed to find a way to match the right message to the right users.

Upon realizing that their buyer personas’ needs hinged on their job expertise, Clearbit decided to segment their welcome email drip campaign based on a user’s role. Take a look at two of these emails that have a 64% open rate.

Clearbit enriched welcome email
click for larger view

The email on the left provides developers a peek into how the Clearbit API operates, showing an example cURL command and the data Clearbit returns. The email on the right, on the other hand, addresses a marketer’s concern, reassuring that building a technical integration isn’t necessary to explore and find value. There’s plenty to do to get started “without writing code” using 3 popular non-technical tools.

To accomplish this message personalization, Clearbit turned to their Clearbit integration with Customer.io. The integration sends new signups to the Clearbit Enrichment API, which passes information linked to the email address, including data points like role and seniority, into Customer.io.

Clearbit enrichment API returning data points example

From there, they created a simple segment based on the role attribute data now in Customer.io.

Clearbit segment

Instead of sending a catch-all email with a generic “check out all the cool things you can do” message, Clearbit addresses specific use cases relevant to their various audiences. As a result, their conversion rates are between 4.9% and 6.3% through the welcome series alone.

Harness user feedback to personalize onboarding

Clearbit continues onboarding people after they become paying customers of their Enrichment API service. Just because a new customer pays for a month or more doesn’t mean they’ve fully adopted a tool. Many will leave a product they don’t totally understand without communicating their needs. Clearbit nips this issue in the bud by directly asking customers how they’re planning to use Clearbit data. Then they send post-purchase onboarding emails based on those self-reported plans.

Once you start paying for the Enrichment service, you’re asked to take this quick one-question survey:

Clearbit customer survey

Each time someone responds to the survey, that gets passed into Customer.io as an event, with their specific answer as an event attribute. Clearbit uses this response data to further group their paying customers—adding segment conditions based on whether customers took the survey and which answer they selected. Here’s what that looks like:

survey-based segment trigger

Clearbit uses these segments to trigger emails tailored to the survey response. Here are two examples:

Clearbit Customer.io survey triggered emails

click for larger view

People who plan to enrich their lead and customer information get the email on the left, which includes helpful tips for how to boost their sales and marketing conversions, all with example case studies. Those who plan to integrate Clearbit with their own product receive the more technical email on the right, with pointers on how to best navigate the API.

The risk of sending the same email to everyone is that the message is irrelevant and fails to resonate (and prompts an unsubscribe). Clearbit doesn’t make their customers do the mental work of cherry-picking their own relevant bits from a message and instead automatically delivers personalized tips.

Deepen engagement based on technology personalization

It’s up to Clearbit to make sure that their customers find long-lasting product value. To deepen engagement, the team points out how customers can use Clearbit with tools they’re already using.

technology-based personalization

The email on the left tells Jan how to get more out of Marketo, a tool he’s already using, by using Clearbit. The same goes for Brian in the email on the right, but with Google Sheets. Instead of sending an email cataloging a laundry list of integrations on offer, Clearbit sends this email addressing a very specific use case. As a result, the email is engaging, the customer is happier, and the product is stickier.

There’s a lot going on behind the scenes of that seemingly simple email. Not only does Clearbit use their own Enrichment API to pass through data points about tools in use into Customer.io, they manage all the message variations in a single email, using Liquid.

clearbit onboarding email using liquid

With Liquid powering “if/else” logic to show different text in both the body and subject line, Clearbit creates one email covering four different use-cases—the integration of Salesforce, Segment, Marketo, or Google Sheets.

subject line personalization

At a 59% open rate, this simple integration suggestion gets a 5.5% click-through rate.


Clearbit built an entire company around the principle that data is paramount. But gathering information is only the first step. It’s even more important that you put that data to good use to create a great experience for your customers.

By getting creative with enriched data in Customer.io and some experimentation, Clearbit came up with a robust email strategy. Clearbit can equip their users to be successful in their businesses, and it pays off big time. Learn how to set up the integration between Clearbit and Customer.io (or via Segment).