As marketers, we understand that the email we’re sending must be intriguing, relevant, and desirable. But we have to remember that email is supposed to be a win-win—brands send more email, and consumers get to see more offers/info relevant to their wants, needs, and actions they’ve taken.

So how can you judge your performance during your email campaigns? One easy metric to monitor that gives you solid insight into whether you’re sending relevant email is Click to Open Rate (CTOR).

What is click-to-open-rate (CTOR)

The best way to think about CTOR is to imagine, of those who opened your email, what percent found the content inside valuable/relevant enough to click on? It can be calculated as (unique clicks/unique opens) x 100. For example, if your email receives 100 clicks, and 150 opens, your CTOR is 66%.

Although metrics like open rates are equally important to track, CTOR helps paints a more complete picture of how your content is performing.

CTOR is different than CTR (click through rate) because the CTOR is based on people who opened your email, rather than your entire recipient list.

Keeping a close eye on your CTOR ensures that you can determine if your content is actually resonating with your recipients (once they were convinced to open your email).

What is the average click-to-open-rate?

Generally speaking, a good CTOR can range between 20% and 30%. However, as with any metric, it’s important to know how you compare with your industry averages. Refer to our 2018 Global Email Benchmark Report to see how you compare to your industry average on unique click to open rate.

How to increase your click to open rate (CTOR)

In order to optimize your CTOR, start with these 5 steps:

1. Calculate your baseline CTOR

If you’re tracking your emails on a campaign level, find your norm for each of your different campaign types. Campaigns with personalized offers will have a consistently higher CTOR, so make sure you’re comparing apples to apples.

2. Incorporate more personalization

Giving customers something relevant and personalized to them will undoubtedly result in more clicks once your customers have opened your email. Use whatever data you have such as pages, products viewed, or products favorited, etc. to serve them something specific to their tastes.

3. Perfect your subject line

Every email marketer shoots for a subject line that will get them the highest possible open rate. I definitely get a feeling of excitement when I think of a clever, or funny subject line, but subject lines serve a bigger purpose than just a “wow” factor.

Opens are great, but only as great as how close it gets you to the final goal: conversion.

If your subject lines are getting opens because they’re funny or abstract, but not because they are representing your copy appropriately—they could cause your email to bounce, so consider providing a more clear and direct subject line.

 4. Provide a persuasive CTA

Focus on including clear and concise calls to action. Make sure your openers know exactly what you’re asking of them.

Read up on Your Top Email Call To Action (CTA) Questions, Answered to make sure you’re covering all your bases.

5. Review your results

When you are reviewing your email campaign metrics, the CTOR is great at gauging how relevant or valuable the content within your email appeared to the recipient. If you see high open rates, but low CTOR rates, this indicates that you nailed the subject line, but left more to be desired on the offering or copy within your email.

On the flip side, if you’re seeing lower than normal open rates, but increasing CTOR, then you can infer that you’re providing recipients with quality content and offerings. To balance these two elements, ensure that you’ve segmented your email list so that your campaigns are fine-tuned and targeted towards the right recipient groups.


SendGrid delivery expert Seth Charles put it well when he said, “Email marketing revenue is not a volume-based metric; it’s a value-based metric.”

This type of thinking is important when fostering a strong relationship with your customer. How can you deliver your customer value through email? Once campaigns go out, tracking your CTOR is a great way to see how you’re doing.

For more on how to optimize your email sending, check out our 4th Quarter Email Playbook which is full of resources to make sure you create your best email campaigns to date—no matter what time of year it is!

Austin is an activation marketing manager here at SendGrid. When he's not planning and scheduling campaigns, he's out filming skateboarding, or hanging with his girlfriend eating Ben & Jerry's (he highly recommends Americone Dream flavor).