When & Why to Test Google Discovery Campaigns

When I was first digging into Discovery campaigns earlier this year, the biggest deterrent to me was the lack of control Google offers with this campaign type. While Google has been taking more and more disconcerting liberties with reducing advertiser insight into our campaigns, I’ve found that Discovery campaign performance has been solid so far.

I want to share some strategies we’ve seen work well, as well as some reasons to consider trying out this campaign type.

Why Discovery Campaigns?

Expand Your Reach

With Discovery campaigns, you get access to the Discover Feed on mobile devices. Regardless of the additional targeting layers you choose, you are getting an intent-driven placement with the Discover Feed that you don’t get with other campaign types. Additionally, as with other Display campaigns, you have the option to use Automatic targeting to further increase your reach, although I’d recommend you test this slowly and cautiously.

In addition to the Discover Feed, your ads can show on the YouTube Home and Watch Next feeds and Gmail Promotions and Social tabs, which combined reaches a whopping 3 billion customers.

Leverage a New Ad Type

Discovery campaigns offer regular Responsive ads as well as a new Carousel format. You can upload up to 10 cards and create an even more eye-catching, engaging interaction for users.

We have tended to see higher engagement rankings from our Facebook carousel ads, so testing this format here makes sense. If you have great visuals available, why not put them to work?

Leverage Lead Forms

Google announced last month that Lead Form ad extensions would be added to Display campaigns this year and they’re already available for YouTube and Discovery campaigns!

To find where to add these, click into a Discovery campaign and head to the campaign settings tab to find where to set these up:

*Note that lead forms are not available for Carousel ads at this time.

Take Advantage of Early Adopter Stats

I’ll cover some more data below for what we’re seeing in our Discovery campaigns, but so far we are seeing lower CPCs and higher CTRs in all Discovery campaigns as compared to regular Display campaigns with the same targeting, whether the Display campaigns are using Responsive or Banner ads.

Our Discovery Campaign Results


For CPCs, we’re seeing anywhere from a few cents lower to 60% lower in Discovery campaigns versus standard Display campaigns.

For CTRs, we’re seeing drastically higher metrics, from 3x to about 6x higher, in our Discovery campaigns vs standard Display campaigns – 3.93% vs 0.67%, 2.33% vs 0.80%, 2.01% vs 0.67%,etc.

Conversion Rates & CPAs

For conversion rates, we’re seeing better performance in Discovery campaigns. For one Sale Remarketing effort, our Discovery campaign gained leads for an $83 CPA while our standard Display campaign spent $450 with no conversions. For another Sale Remarketing effort, we saw a 1.45% conversion rate and a $42 CPA in Discovery vs a 0.56% conversion rate and a $137 CPA in standard Display.

For an Evergreen content Remarketing effort, we saw a 2.38% conversion rate and an $18 CPA in Discovery vs a 1.16% conversion rate and a $39 CPA in standard Display.

Site Metrics

Overall, we’re seeing lower bounce rates, more pages visited and longer time on site for Discovery campaigns.

Bidding Differences

I’d like to note the difference in bidding strategies for our Discovery and regular Display campaigns. For Discovery, you can only choose tCPA bidding, which is what we have used, or Maximize Conversions. In our standard Display campaigns, we’ve used either Manual or Enhanced CPC bidding. It’d definitely be worth it for us to set up experiments to test the same target CPA strategy in our standard Display campaigns to have more of a head-to-head comparison.

Overall, our sample size is pretty small for Discovery campaigns, but the metrics so far are promising.

When to Test

There are lots of worthwhile reasons to give Discovery campaigns a shot, including the following:

  • If you’ve tested standard GDN campaigns in the past and haven’t had much luck, consider giving Discovery campaigns a try. They’re more intent focused and, for now, are garnering cheaper CPCs. You could start with Remarketing to dip your toe in the water and go from there.
  • As mentioned above, Discovery campaigns could be a great, intent-focused way to grow leads for your account. Whether you’re looking to fill the top of your funnel with content offers or you’re looking to drive more bottom-funnel conversions, Discovery campaigns can work well if you’ve got good targeting in place, strong visuals, and set a reasonable target CPA for your campaigns.
  • Speaking of visuals, if you have strong images then Discovery carousel variants especially are a great way to showcase them and draw users in.

However, if you don’t have a strong Mobile site you should reconsider testing Discovery at this time. We’ve seen more than 90% of our impressions coming from Mobile devices, so if you can’t offer a good user experience I’d try different campaign types or work on improving your Mobile experience.

Have you tested Discovery campaigns? Let us know what you’re seeing in the comments below!