The Cross-Channel Question Nobody Was Asking Loudly Enough
For years, the marketing measurement world has been split in two. Digital teams measure everything obsessively — clicks, sessions, conversions, ROAS down to the decimal. Offline teams measure reach and frequency, and trust that "brand building" eventually pays off. The bridge between these two worlds has been mostly anecdotal.
That's why a peer-reviewed study from Erasmus University Rotterdam landed with such weight. Published in the International Journal of Web Engineering and Technology, researchers Nibbering, Frasincar, and Vandic set out to answer a question that sounds simple but had never been rigorously tested at scale: do TV and radio commercials actually cause people to go online and convert?
The answer, backed by 600,000 conversion paths from a real campaign, was unambiguous: yes — and the effect is larger than most media buyers assume.
The Study: Lays "Do Us A Flavor" Campaign
The researchers analyzed a real consumer campaign run by Lays in the Netherlands in 2012 — the "Do Us A Flavor" competition, where consumers were invited to submit new chip flavors online. It was the ideal test case: a defined offline media spend (TV and radio commercials) driving a specific online action (visiting a website and entering a competition).
Every conversion path — the sequence of exposures and actions before a submission — was recorded. The dataset captured broadcast schedules for every TV and radio spot, mapped against the timestamps of online visits and form submissions. This gave the researchers a granular view of the relationship between offline media events and online behavior.
"TV and radio commercials positively influence online conversion actions — and the effect can be measured with statistical precision using distributed lag models applied to real campaign data."
Three modeling approaches were used: Ordinary Least Squares (OLS), Support Vector Regression (SVR), and distributed lag models. The distributed lag model proved most accurate, as it could capture the time-delayed nature of the effect — viewers don't always act immediately after seeing an ad.
Key Finding #1: Both TV and Radio Work — TV More So
The core finding confirmed what many media planners intuitively believed but couldn't prove: both TV and radio commercials generate measurable increases in online conversion actions. This isn't correlation — the researchers controlled for time of day, day of week, and competitive scheduling to isolate the causal effect of each broadcast.
TV consistently showed a stronger effect than radio. The visual and audio combination of a TV spot drives a more immediate and pronounced online response. Radio's effect was real and statistically significant, but roughly a third of TV's impact per spot.
Even a single TV broadcast generates a statistically detectable spike in online conversions — and the effect doesn't stop at first click. The halo extends across the conversion funnel, influencing users who arrive hours later via organic search.
Key Finding #2: Channel Context Matters More Than Reach
One of the most practically useful findings from the study concerns channel selection. The researchers compared performance across different broadcaster types and found a consistent pattern: general-purpose channels dramatically outperformed specialized, niche channels for driving online conversion actions.
Spots that aired on RTL4 and Comedy Central — broad-appeal entertainment channels — generated significantly more online visits than equivalent spots on National Geographic or Animal Planet, even when raw audience size was controlled for.
The implication is counterintuitive for advertisers who chase audience targeting: when your goal is to drive online action, being seen by a broader, less targeted audience can outperform niche placement. Context alignment matters — a consumer actively watching general entertainment is more receptive to a participatory, online-action-oriented campaign than one in "documentary mode."
Key Finding #3: The First 50 Minutes Are Everything
The distributed lag analysis revealed something critically important for media planning: the effect of a TV commercial on online conversions peaks within the first 50 minutes after broadcast, then decays rapidly.
This has direct implications for campaign scheduling. If your offline media is meant to drive online actions — site visits, form fills, purchases — the window is narrow. Campaigns that broadcast heavily during the day but direct users to a website that's slow or unavailable in the evening hours are losing a significant portion of their ROI.
"The conversion spike peaks in the first 50 minutes. After that, the marginal impact of a single broadcast drops off sharply — which means scheduling isn't just a reach question, it's a conversion optimization question."
Why This Research Still Matters
This study was published in 2013, using 2012 data from a Netherlands campaign. You might wonder whether its findings hold in a world of streaming, second screens, and fragmented media consumption. The answer is: more than ever.
The mechanisms the researchers identified — offline stimuli driving search behavior, which then drives conversions — have only intensified as consumer habits have shifted online. More people than ever are sitting with a phone in hand while watching TV. The pathway from offline exposure to online action has become shorter, not longer.
What's changed is the measurement infrastructure. In 2012, connecting TV schedules to website analytics required custom research projects. Today, platforms like Animo can track this relationship in near real-time, using attribution models that capture the full offline-to-online conversion path across every channel simultaneously.
What This Means for Your Media Strategy
The Erasmus study gives media planners a rigorous academic foundation for something they've argued intuitively: offline media isn't just brand building — it's a direct performance driver. Here's what that means practically:
- Schedule offline media to align with your highest-converting online hours — don't treat TV scheduling and digital campaign timing as separate decisions
- Measure the 50-minute post-broadcast window explicitly — if you're not tracking search volume and site visits in that window, you're attributing offline impact to "organic"
- Don't assume niche channels outperform broad ones for conversion-driven campaigns — the data says the opposite
- Model radio and TV separately in your MMM — their impact curves and decay rates are genuinely different
- Treat offline spend as a performance investment, not just a brand investment — the ROI is there, but you have to measure it
Most brands running offline media today have no mechanism to capture the 50-minute post-broadcast conversion spike. They see organic search lifts but attribute them to SEO. They see direct traffic spikes but attribute them to other digital activity. The offline halo is real — it's just invisible without the right measurement infrastructure.
The Bottom Line
The Erasmus University study is a rare thing in marketing: a rigorously controlled, peer-reviewed proof that offline media drives measurable online outcomes. It validates the cross-channel halo effect with real campaign data, at scale, using multiple statistical methods.
For media planners still defending their TV and radio budgets to skeptical CFOs, this is the kind of evidence that changes conversations. Not "we believe offline drives awareness." But: "here is a causal model, run on 600,000 conversion paths, showing that offline media drives online conversions — and we can measure it the same way."
The only question is whether you have the measurement infrastructure to capture it.
Original Research: Nibbering, D., Frasincar, F., & Vandic, D. (2013). "Analyzing the Effect of Offline Media on Online Conversion Actions." International Journal of Web Engineering and Technology. Erasmus University Rotterdam.