Campaign cannibalisation, a bug bear of the pMax campaign ecosystem, ways to navigate this issue and what we actually mean by Cannibalisation!

The Problem: Overlapping Keywords

Let’s consider a hypothetical case where you’re running two separate campaigns for a home furnishing company. Campaign A is focused on “luxury sofas,” and Campaign B is geared towards “designer couches.” On the surface, these might appear to be distinct, but in the eyes of pMax, they could overlap significantly.

The overlap might lead pMax to display ads for Campaign A to people who are more interested in the products from Campaign B, and vice versa. What you’ll end up with is an internal competition, essentially bidding against yourself. This is what we mean when we talk about cannibalisation, and it can lead to distorted metrics. For example, your cost per acquisition (CPA) may rise because you’re not efficiently targeting.

The Solution: Structured Campaigns and Tiered Bidding

Structured Campaigns

The first step to mitigate cannibalisation in pMax campaigns involves a bit of a workaround. Although the Google Ads UI doesn’t directly allow you to add negative keywords for pMax, you can request this by contacting your Google representative. For example, you could request that “designer” be applied as a negative keyword for Campaign A, and “luxury” for Campaign B. This ensures that each campaign remains more focused on its unique target audience.

Doing this essentially creates a boundary between the campaigns, helping to minimise internal competition and allowing each campaign to perform at its optimal level. It’s an extra step, but in the world of pMax, it’s often these extra efforts that set the stage for a more effective campaign.

Tiered Bidding Strategy

Another approach is to implement a tiered bidding strategy based on keyword value and relevance. For instance:

  1. High-Value Keywords: These are keywords closely aligned with your product and have proven to convert well. Set your target ROAS aggressively on these.
    • Example: For Campaign A, “handmade luxury sofas” could be a high-value keyword.
  2. Medium-Value Keywords: These are generally relevant but perhaps broader or less aligned with your specific products. Set your target ROAS moderately here.
    • Example: “Leather sofas” could fall into this category for Campaign A.
  3. Low-Value Keywords: These are broader still and may attract a wider audience, not all of whom are necessarily interested in your specific offering. Set your target ROAS conservatively.
    • Example: A simple “sofas” might fall into this category.

Advanced Tactics: Keyword Grouping

If you’re looking for a more advanced strategy, consider keyword grouping. For instance, group similar high-value keywords across different campaigns and apply a uniform bidding strategy to them. This ensures that you’re not underbidding or overbidding on similar keywords across different campaigns.

Conclusion: The Balancing Act

By taking a more structured and strategic approach to keyword selection and bidding, you can prevent cannibalisation, thereby making your campaigns more efficient. It may involve a bit more upfront planning and ongoing management, but the end result is a more effective, more efficient advertising effort.

In essence, avoiding cannibalisation is a balancing act, one that requires an in-depth understanding of your keywords, your audience, and the pMax platform itself. But get it right, and you’ll find that your campaigns are not only more effective but also more cost-efficient.