Cookie Bombing: A Dark Art the Advertising Industry Must Leave Behind

The advertising industry has been talking about a cookieless world for over five years. While that reality continues to be delayed, I want to address a problem that this shift might (hopefully) resolve—cookie bombing.

The ‘art’ of cookie bombing should be considered a dark art. It may not quite be Avada Kedavra, but it’s certainly close to Cruciooooo!

This practice isn’t just unethical—it’s unforgivable.

What Is Cookie Bombing?

Cookie bombing, also known as "cookie stuffing" or "cookie dropping," is a deceptive advertising tactic where tracking cookies are placed on users' devices without their active engagement with the advertised site. This tactic distorts attribution data, allowing advertisers or affiliates to claim credit for sales or leads they didn’t genuinely influence.

In many cases, this leads to agencies claiming the credit for conversions they didn’t truly achieve.

Originally, cookie bombing thrived in the affiliate marketing world. Some affiliates would stuff cookies onto users who simply visited their site. When those users made purchases elsewhere, the affiliates claimed the conversion—despite having no real impact on the sale.

The Tactic: Inflating Performance Through Deception

Today, cookie bombing has evolved. Some vendors and agencies exploit less-experienced brands and agencies that don’t use ad servers to monitor campaign performance. They artificially inflate success by targeting users already on the brink of conversion.

Here’s how it typically works:

• Cheap Inventory: Targeting low-cost, remnant ad placements.

• Low Bids: Prioritizing impressions with minimal cost.

• Strategic Bidding: Aggressively bidding on the third impression—the point where users are statistically more likely to convert.

One common method I’ve seen personally involves:

1. Restricting impression delivery to low-quality, remnant inventory.

2. Targeting full-site retargeting segments.

3. Pinpointing the cheapest audience segment nearing conversion.

4. Bombarding this segment with low-viewability, often questionable placements.

   
   

Why Cookie Bombing Is Unforgivable

Cookie bombing isn’t just a dark art; it’s harmful to the entire advertising ecosystem. I’ve been asked to engage in this tactic countless times. Directors and salespeople have often told me, “But other platforms do it.”

My response? we are better than that.

What do we stand for as professionals? We should all stand for integrity, transparency, and real results.

Sure, traditional analysis and optimization take longer, but they deliver better, more sustainable performance when executed correctly.

As marketers, we have a choice:

• Take the easy, unethical route (Crucio!).

• Or do the hard work that builds trust and delivers authentic value.

Please choose wisely.

How to Spot Cookie Bombing

If your campaign’s CPA (Cost Per Acquisition) suddenly drops, don’t assume it’s just bad luck. Take a closer look and ask these questions:

• Is viewability compromised? Are your ads being served in hard-to-see placements?

• How safe is your brand? Are you appearing on questionable domains?

• Has the inventory changed? Compare your current ad placements with those used before the performance drop.

More often than not, unethical practices like cookie bombing are the culprits behind sudden and rapid performance improvement.

Looking Ahead: The Cookieless World

As we transition into a cookieless future, we must leave behind harmful tactics like cookie bombing.

Let’s be honest—this dark art is already evolving into new forms, such as pixel stuffing.

But that’s a topic for another day.