When you implemented a cookie consent banner on your website, you will have noticed some changes in your Google Ads performance. The most efficient smart bidding strategies rely on accurate data. Most advertisers should be using target CPA or target ROAS. Today, let’s talk about why you need to adjust your smart bidding strategies to accommodate the reduced tracking.
Why you need to adjust smart bidding strategies
This really should have all been done back in March 2024 when the Digital Markets Act came out and probably sooner with GDPR. Google no longer shares audience data between Ga4 and Ads without consent mode v2. Some people ignored this with little consequence as it mainly affected retargeting which many advertisers don’t use. .
Recently though, Google has been checking and even threatening to withhold conversion data.
From Chris in the PPC Live Chat Whatsapp Group.
If your conversions have suddenly stopped working in Ads it could well be because consent mode is not set up.
Understanding what’s going on.
When you add a cookie banner, a portion of your website visitors will inevitably not optin to tracking. This means Google Ads won’t be able to track these users’ behaviours, leading to incomplete conversion data. In a previous article, I talked about the consequences of a tucked away cookie banner . This isn’t just a minor inconvenience when looking at your stats – it can significantly impact your smart bidding performance.
Let’s do the numbers
Here’s a practical example:
- Original Target CPA: £100
- Percentage of users opting out: 20%
- New Required Target CPA: £125
Why the 25% increase? When you lose visibility on 20% of your traffic, you need to adjust your target CPA upward to maintain the same actual cost per acquisition. The formula works like this:
New Target CPA = Original Target CPA / (1 – Opt-out Rate)
£100 / (1 – 0.2) = £100 / 0.8 = £125
Think of it this way: if you were previously getting 10 conversions at £100 each (£1,000 total spend), and now you can only track 8 of those conversions due to cookie consent opt-outs, you need to be willing to pay more per tracked conversion to maintain the same overall performance.
Practical Steps to Take
- Monitor your opt-out rate: Track what percentage of users are declining cookies
- Calculate your new target: Use the formula above to determine your adjusted target
- Gradually implement changes: Don’t make dramatic changes overnight
- Keep monitoring: Watch your performance metrics closely after making adjustments
Additional Considerations
- Different markets have different opt-out rates
- Consider seasonal variations in user behaviour
- Keep an eye on your overall Marketing Efficiency Ratio (MER), not just CPA
- Test different cookie banner designs to optimise consent rates. There are ways to optimise banner opt-ins (some more compliant than others!).
Remember, this adjustment isn’t about spending more money per lead – it’s about accurately reflecting your true acquisition costs in a world where not all conversions can be tracked.
Other things you can do.
Set up Enhanced Conversions
Google are ramming enhanced conversions down our throats with overly dramatic language and red warning.
If you can get it past your DPO, it’s actually something you should do. This not only helps with cookies but also helps with cross-device tracking. For example, if somebody searches on mobile and converts on desktop, no cookies can track that but with enhanced conversions you can.
Offline conversion tracking
There are multiple ways to do offline contract version tracking, but the most common way to do it is to use Zapier. You can see the list of integrations here
Basically, what you do is you capture the gclid and just upload that via Zapier. The official documentation for this is here and more information can be found here
Summary
Implementing a cookie banner is essential, but it requires thoughtful adjustments to your Google Ads smart bidding strategies to maintain desired outcomes. By understanding the impact on your conversion tracking and adjusting your target CPA/ ROAS accordingly, you can continue to drive results and ensure that your campaigns remain effective in a more privacy-conscious environment. Adding offline conversion tracking and enhanced conversions can further reduce the impact of data loss.
