Guide to Discovery Ads: Benefits, Key Dimensions & Best Practices
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Mary Liversidge
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Google Discovery ads are an effective way to reach your target audience on high-traffic platforms such as YouTube and Gmail.

In this article we guide you through what Discovery ads are, how they are useful, creative requirements, and our tips on best practices.

What are Discovery ads?

Discovery ads appear as images accompanied by headlines and descriptions. These image & text ads can appear in 3 key placements:

  • YouTube

  • Discover network

  • Gmail

According to Google, these placements enable advertisers reach up to 3 billion users monthly, and the context in which consumers use these platforms (to discover new information or entertainment) makes these ads a desirable prospect.

Discovery ads come in two formats:

  1. Standard discovery ads = single static image with headline and description

  2. Discovery carousel ads = multiple images accompanied by headlines and descriptions in a carousel format where users can scroll through them

Each ad set requires multiple images, headlines and descriptions which Google uses interchangeably depending on the audience. Using AI, Google automatically displays the most relevant combination for the person seeing it.

Who are they suitable for?

Discovery ads are ideal for companies who want to reach new customers with their content or reconnect with previous customers who have engaged with the company’s ads, website, or YouTube channel.

What are the benefits of Discovery ads?

  1. Deliver diverse & relevant content

Because of Google’s algorithm and requirement for a collection of creatives, discovery ads are an excellent way to show relevant ad content to users depending on their interests, needs, and stages of the buying journey.

The diverse combinations of creatives that can be shown to any one user also reduces the likelihood of ad fatigue (when a user becomes tired of repeatedly seeing the same creatives) which can easily turn users off a brand.

  1. Reach customers in an open-minded ‘discovery’ state

The placements the ads appear in (YouTube, Discover network and Gmail) are, according to Google, a great opportunity to reach customers who are in a ‘discover’ phase i.e., in the pursuit of entertainment and information.

In other words, they are open to new ideas - which can increase the chances of users being engaged by an ad and leading them to pursue the product or service being advertised.

  1. Lower average CPC and higher conversion rate than Display Network

When the same audiences are targeted on Display and Discovery campaigns, we have found Discovery campaigns average CPC to be 21% lower, conversion rate 242% higher and the cost per conversion to be 77% lower than Display.

  1. Safer placements for advertisers

There’s a lower chance for click fraud on the Discover network as all placements are Google owned sites, rather than placements on the Display network.

  1. Wide reach

With over 3 billion monthly active users of these platforms, the opportunity to reach customers is vast.

Discovery ad dimensions

Google has specific requirements for the creatives (or assets) including dimensions to cooperate with its algorithm.

Ad requirements:

  • Headlines

    • Standard discovery ads - Provide up to 5 headlines

    • Carousel discovery ads - Provide 1 headline for the ad set and 1 headline for each card on carousel

    • Limited to 40 characters per headline

  • Descriptions

    • Standard discovery ads - Provide up to 5 descriptions

    • Carousel discovery ads – Provide 1 description

    • Limited to 90 characters per description

  • Images:

    • Provide up to 20 images for standard discovery ads

    • Provide up to 10 images for carousel discovery ads – carousel ads will display all the images uploaded and they will appear in the order you upload them

    • Dimensions must be one of the following:

      • Landscape (1:91:1)

      • Square (1:1)

      • Portrait (4:5)

      • Logo – (1:1) Square logos will be cropped into a circle

  • Business Name

  • URL – product-specific pages (i.e. product detail pages) are best

​​​​​​​Best practices

It’s important to get discovery ads right, and by optimising your campaigns you can ensure they are providing relevant, targeted information to your target audience.

  1. Use targeted ad copy

Make sure to diversify your copy to appeal to users at different stages of the buying journey. Make the most of the maximum headline and description limits to make sure that your ad covers as many stages as possible, and to help Google provide the right information to the right viewers.

It is also important to ensure your copy corresponds to your business’ tone and style on the rest of your channels – including your website, and titles and descriptions should read like content and full sentences instead of pure product names.

Use a combination of promotional copy (with offers and deals) and more natural copy about your brand (native copy).

As a general rule, promotional copy works well with Gmail placements as users tend to be on the hunt for offers, and more general brand copy works well on the discover feed.

  1. Use high-quality, eye-catching images

Your ad could be the first impression a customer has of your brand, so it is vital that images and copy are of excellent quality.

Check your ads in the preview tool before making live to ensure there are no typos and that images are not pixelated, too busy, or too sparse.

Google offers some guidelines regarding how images should appear – including to:

  • Avoid busy backgrounds that clash with the text

  • Avoid images too close up or too far away

  • Use high resolution images

  • Avoid using too much text in the images themselves

  1. Reach the right customers

Make use of Google’s targeting tools to ensure you reach the right customers. Discovery campaigns can target users based on their characteristics and search intent. Google has pre-defined audiences through In-market and Affinity audiences, and custom audiences can be created based on users’ behaviour, such as users who have searched for terms. These are particularly good for more niche products or services that don’t fit within Google’s pre-defined audiences.

  1. Don’t make changes straight away

It is important to give Google’s AI technology time to learn from the data it is harvesting. As a result, it is best practice to give your ads 2 weeks after set-up before making any changes (unless of course something is going drastically wrong).

This will give Google’s algorithm the chance to understand the data, helping it to optimise the campaigns and deliver the right ad with the right combination of image and copy to the right person.

  1. Set the right budget – and stick to it

Likewise, Google recommends choosing a daily budget at least 10 times higher than the value of your target cost-per-action (tCPA) and waiting until the campaign achieves at least 40 conversions before making any changes.

This is again so that the algorithm can gather enough data to be able to optimise the campaign effectively.

Our thoughts

Our PPC Manager, Jerry, comments:

Discovery ads have been incredible for the accounts we have tested them on. Some accounts have generated conversions at a lower cost than non-branded search campaigns. With more advertisers trying them out, it’s important to test them out sooner rather than later. We have seen average CPC’s increase by over 100% YoY as uptake increases. Even with the increase in average CPC, the campaigns still significantly outperform other non-search campaigns.”


At TDMP, we provide bespoke, highly targeted PPC campaigns to achieve valuable clicks and conversions for our clients. For more information about our services or an informal chat about how we can help your business, get in touch.