Why Foot Traffic Does Not Mean Growth
Updated: 2 days ago
As part of our ongoing series on growth and measurement for CPG brands, we've spent the last few posts pulling apart metrics that look like proof of growth and turn out to be something much thinner. Sales spikes that hide rising risk. Share gains that evaporate the week a promotion ends. Now we're going after a metric that gets treated like gospel in more media decks than it should: foot traffic.
Here's the pitch you've probably heard a version of. Someone saw your ad. Then a device tied to that person showed up at a store. Therefore, the ad worked.
It didn't prove that. It didn't prove much of anything.
The misconception: a store visit means the ad worked
Foot traffic attribution measures one thing, and only one thing. Whether a device appeared inside a geographic boundary sometime after an ad ran.
That's presence. Not purchase.
The story everyone wants to tell from that data point goes something like: the ad drove someone to the store, so it drove sales. But a store visit doesn't tell you what that person bought. It doesn't tell you if they bought your product at all. It doesn't tell you whether the ad influenced them in any way. And it definitely doesn't tell you whether they were headed there anyway before they ever saw your ad.
Baseline behavior: the noise that swallows the signal
Here's the part that makes foot traffic especially weak for CPG specifically.
Most people go to the grocery store constantly. Weekly, sometimes more. That's not a niche behavior triggered by clever advertising. That's just how households function. Someone needs milk. Someone's out of dish soap. Someone forgot the thing they meant to get on Tuesday.
When an action is already that common, measuring whether it happened tells you almost nothing about why it happened. The baseline is so high that any advertising signal gets buried under normal human behavior. You're not detecting a spark. You're detecting people doing what people do every single week, ad or no ad.
Think about your own habits for a second. How many trips have you made to a grocery or drugstore this month? Now think about how many of those trips you can actually trace back to a specific ad. Probably none. That's the gap foot traffic attribution is trying to paper over.
Presence vs. purchase: the leap nobody should be making
Even if you set the baseline problem aside, foot traffic still only gets you as far as the parking lot.
It can't tell you if the person walked in and bought your product. It can't tell you if they walked in, grabbed a competitor's item sitting right next to yours on shelf, and left. It can't tell you if they bought nothing at all and just picked up a prescription. Presence and purchase are two entirely different events, and foot traffic attribution only ever measures the first one.
This is a targeting tool wearing a measurement costume. Foot traffic data can be genuinely useful for identifying and targeting shoppers of a certain retailer or chain. That's a legitimate use. But using it to claim credit for sales, or to justify shifting budget toward the channel that produced the most store visits, is a different exercise entirely. And it's not one the data can support.
What a foot traffic report won't tell you
A foot traffic report will not tell you:
Whether the person purchased anything at all
Whether they purchased your product specifically
Whether the ad had any influence on the visit
Whether the visit would have happened without the ad running
What it will tell you is that a device moved through space. That's it.
A quick fairness check: this isn't true everywhere
Before you write foot traffic off entirely, it's worth being precise about where this problem actually lives.
For a QSR brand, foot traffic basically is the sale. Someone walks into the store, and the overwhelming majority of the time, they walk out with a transaction. Same with a lot of retail chains. In those categories, a visit and a purchase are close enough to the same event that foot traffic can be a legitimately strong, highly correlated KPI.
CPG is a different animal entirely. A grocery store visit doesn't mean someone bought your brand, your category, or anything at all. It just means they went to a place they go to constantly, for reasons that have nothing to do with your ad. That's the baseline problem we just walked through, and it's specific to how CPG shopping actually works.
So the metric isn't broken. It's just being asked a question it was never built to answer for this category.
The bigger picture
Foot traffic measures movement. For some categories, that's close enough to the outcome that matters. For CPG, it isn't, and no amount of clean charting closes that gap.
The reason this metric persists in CPG decks anyway isn't that it's rigorous. It's that it's fast. It updates quickly, it produces a tidy dashboard, and it offers reassurance when real sales data is slow to arrive. That combination makes it easy to lean on and easy to over-trust, especially when nobody in the room is asking the baseline question out loud.
Foot traffic can earn a seat at the table as context. It should never be handed the microphone as proof.
Next up in the series, we're staying in this same neighborhood and looking at website visits after ad exposure, another proxy metric that gets mistaken for a conversion signal far more often than it should.
We are Left Hand Agency, a CPG media buying agency helping brands grow with short and long-term strategies. Our memory-driven strategies deliver results your marketing and finance teams will champion.
