Stop High CPC in Performance Max: The eCommerce Guide to Lowering Ad Costs

Question from Reddit user:

How come our Shopping and Performance Max campaigns are super expensive (1.2 – 2.5€ per click)

Hi,

Does anyone have any ideas what could be wrong? Our ads are super expensive, especially Performance Max. We are a sustainable clothing brand with a AOV of around 73€. Would the cpc stabilize if we let it run for a couple of days?

Thank you

The short answer is:

The long answer is:

The price you’re seeing per click is definitely high, especially for a sustainable clothing brand, but within a competitive niche like clothing with a respectable AOV of 73€, it’s not entirely unheard of for PMax to bid aggressively at the start.

Google’s machine learning, which powers both Shopping and PMax campaigns, requires a considerable amount of high-quality conversion data to exit the “learning phase” and begin optimizing bids efficiently.

If you’ve just launched, yes, letting it run for a bit longer – perhaps a week or two – is crucial, as the system needs time to collect data on which clicks are actually converting and at what value.

However, high initial CPC is often a sign of data quality issues or a very broad audience signal.

For PMax specifically, ensure your audience signals are as targeted as possible, using customer lists and highly relevant custom segments.

The most common reason for sustained, high CPC in automated bidding is poor conversion tracking.

Google may be under-reporting conversions or receiving the data with too much delay, leading it to overspend on clicks that it can’t definitively link to a sale.

This is where server-side tagging and the Google Ads API come in as an excellent and cost-effective solution.

When you use client-side tracking (standard Google Tag Manager setup), a lot of data is lost due to browser restrictions (like Intelligent Tracking Prevention or ITP) and ad blockers.

By implementing server-side tagging via GTM and a solution like Stape or GCP, you move the tracking logic to a cloud environment.

This ensures that the Standard Events, such as purchase, add_to_cart, and view_item, are sent directly and reliably from your server to Google, bypassing many of the browser limitations.

This gives Google a much clearer, more complete, and faster picture of your conversions.

Furthermore, you can leverage the Google Ads API to implement enhanced conversions.

This involves securely hashing and sending first-party customer data (like email or phone number) from your server directly to Google.

Google then uses this to match conversions that might otherwise be missed.

This dramatically increases your conversion match rate, giving the bidding algorithm the precise data it needs to lower your CPC because it becomes more confident in which clicks are valuable, allowing it to bid less on non-converting clicks.

Using Stape, which is often very affordable at its base tier, or a simple setup on GCP, is significantly cheaper and more stable than dealing with the revenue loss from poor attribution.

This improved data quality is the key to stabilizing and ultimately reducing your CPC and improving your overall return on ad spend (ROAS).

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