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Digital Marketing - Study Notes:


Next, we'll discuss images. What should you consider when designing email templates that use email images? What are the pros and cons of using email images? And what are the best practices for using images. Let's dive in and explore the hows, whys, why nots of emails and imagery.

So the first question is, should you use images? If so, how many?  What's too many? And first of all, yes, you should be using images and it is really important for driving conversions and promoting your brand. You have to strike a healthy balance between using images in a way that will benefit your performance and using text.

What you don't want is to detract from conversions because of overloading it with images.

Let's see how images can be used in your emails. You can embed an image which means you attach the image or the second method is to provide a URL reference to the image located on your server, the same way you would a web page.

We'll look at the pros and cons for both to help you decide which is best for email deliverability and conversions.

Embedded images

With image embedding, essentially, you are attaching inline image to the email using HTML image tags that reference the image. The main advantage to this approach is that recipients are sure to get the image whether they download it or if it's displayed in the email.

The cons to this approach are that it increases the overall size of the email causing varying results across email clients and higher spam scores as spam filters look out for large embedded images. Another thing to be aware of when embedding images, unfortunately, image files are used to plant viruses on computers.

To combat this, most email service providers set the default setting on delivered messages to images off, meaning that a large percentage of your emails with images do not get seen unless email users turn on image viewing.

Image link

The second way to add images to your email, an image link, provides an attached URL references which comes with its advantages and disadvantages as well.

In comparison to embedded images in the email, it's less technical, requires very little effort, and it keeps the email weight light meaning you won't get caught for spamming. The downside to this approach is that the recipient will need to actively turn on image viewing in their email settings to see the image. As we've seen, both approaches come with their pros and cons.

The best way to figure out what will suit your email campaign means you need to look at the marketing emails you've seen from large scale companies, view the code. So, for example, in Gmail, you can click show original and look at their email headers, discover what's working for them, and apply it to your own.


There are a number of factors to consider when including images.

  • Email is different from traditional marketing: As with all digital marketing activities, the delivery differs from traditional marketing and specifically print. Your approach to email marketing needs to focus on usability as well as aesthetics. Email is not like a print brochure or a mailer as it does not have the same flexibility as print would, therefore conversions rely on your email images encouraging the recipients to click and to take action.
  • Not all ESPs will display your email images: You must consider usability, enabling the option for images to be turned off but still be able to convey your message clearly. Your email needs to be designed to appeal to your entire subscriber base including those who did not see the images.
  • Avoid overusing images: Another important consideration to make is that overusing images or a bad use of images in an email can result in your email being sent to the spam folder. If you do experience a deliverability issue, one of the first steps you can take is to remove some images from your email and see if performance improves.

Best practices

So, we've discussed the importance of using imagery in email, how to embed them and what the downfalls are to consider and avoid. Now we will look at the best practices and top tips for using images in your email campaigns.

  • Use brand assets: Your brand guidelines may specify what types of photos are and are not allowed on the website. So, this should also apply to your emails because you need to have a consistent experience for the reader.
  • Include product photos: It helps to include images of your product if it's a product email. For example, the new iPhone in Apple's emails or the product you recently viewed in Amazon's triggered emails for an unfilled basket.
  • Size your images: An important thing to note is that your images should be sized correctly. If the image contains text, make sure it is clearly legible and not distorted.
  • Use pixel tracking images: After you have designed your email, you will want to know how many times it was opened. When creating your email, you may need to add a tracking pixel. A tracking pixel is a one by one pixel, transparent image added to the code of your email. So when a user opens your email, the image is downloaded letting the tracking software know that the email was actually opened. Some ESPs will also add the tracking pixel automatically so double check with your email service provider if you have to actually add it manually. Gmail will cut images that are too large, at this moment, it is 102kb in file size, and only display the top portion to the user. Therefore, you are manually adding the tracking pixel it will add towards the top of the email, so they're open to track.
  • Use the less than 25% rule: Alternatively, you can also ensure your email isn't too big. When deciding how many images you should include, refer to the less than 25% rule. As in, no more than 25% of your entire email should be image-based. You want the 75% of the email to be readable, as in text-based without images.
  • Include alt text: Some ESPs may default to images switched off so your email standing alone needs to be able to convey the message that the images were going to tell. This can be accomplished through the alt text.
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Please note that the module slides are designed to work in collaboration with the module transcript document. It is recommended that you use both resources simultaneously.

Digital Marketing Resources:

Andrea Francis

Inbound marketing manager @ Poppulo

  • Inbound marketing manager in employee communications technology 
  • Worked at Relayr as a senior marketing manager, creating and implementing a global inbound marketing strategy
  • Worked with Hubspot as a marketing manager and funnel optimization specialist focusing on converting leads to qualified leads for the EMEA region
  • Content marketing and blogging with various SaaS startups at Startupbootcamp Amsterdam

The following pieces of content from the Digital Marketing Institute's Membership Library have been chosen to offer additional material that you might find interesting or insightful. While relevant to this module, you will not be assessed on this content.

You can find more information and content like this on the Digital Marketing Institute's Membership Library


Email Marketing
Andrea Francis
Skills Expert

This module begins with the fundamentals of email marketing and how the concepts of segmentation, personalization, timing, engagement, and the legislation and regulations surrounding data protection underpin an effective email marketing strategy. The module introduces key email marketing tools and techniques and explores subscriber list and email design best practices. It covers how to create, test, and optimize an email campaign that maximizes email open and click rates and provides an overview of the value provided by marketing automation tools.