If you’ve ever watched website traffic move in lockstep with a TV flight, you’ve seen the core challenge up close: TV can influence demand in a way that’s real and measurable, but often hard to separate into clean channel-by-channel boxes.
We wanted to get a closer look at how and when TV is most effective, and under what conditions it actually drives incremental demand.
To answer that, we analyzed nearly two years of website session data for a client, a national leader in hearing health with over 380 centers across the US, to measure the impact of local TV, national TV, and CTV on website traffic. The analysis focused on two comparable Southwest markets, Phoenix and Tucson, using a controlled test design that allowed us to isolate incremental lift rather than rely on correlation or blended attribution models.
We saw a clear pattern: different forms of TV play fundamentally different roles in driving demand, and confusing those roles leads to inefficient investment decisions.
The analysis was designed to address two planning questions that media teams routinely face:
- Does local TV drive incremental website demand relative to a comparable market without local investment?
- Once local TV ends, can national TV or CTV sustain that lift?
These questions matter because they sit at the center of how budgets are allocated, particularly when national reach is often positioned as a substitute for local execution.
Our Methodology
We looked at the two years of daily GA4 website session data across Direct, Organic Search, and Paid Search, with Phoenix as the test market, with clearly defined local TV on/off periods, and Tucson as the control market, with no local TV activity.
By aligning session performance with precise media activation and pause windows, we were able to observe how traffic responded when media entered and exited the market.
After September 15, when Phoenix local TV ended permanently, all subsequent performance was attributed only to national TV or CTV, ensuring local lift was not overstated. This allowed us to evaluate TV as an active demand driver rather than a passive branding input.
Phoenix Local TV Delivered Incremental Lift
During both Phoenix local TV flight periods (4/21-7/13 and 8/4-9/14), Phoenix outperformed Tucson across all high-intent channels.
Total website sessions increased 15-25% above baseline. Direct traffic showed the strongest response, rising 50-70%, while paid search increased in close alignment with TV air dates. Organic traffic remained stable in Phoenix during these periods as Tucson declined seasonally.
The response was immediate and pretty clear: sessions rose when TV turned on and fell when it paused, leaving little ambiguity about what was driving demand.
What Happened When Local TV Went Dark
Two distinct pause periods reinforced the findings: during the July pause (7/14-8/3), Phoenix sessions fell roughly 35% week over week, compared to a 15-20% decline in Tucson, while Phoenix’s performance advantage largely disappeared.
The same pattern repeated after September 15, when local TV ended permanently. Traffic declined again, with no sustained separation from the control market. Lift proved dependent on active media support.
Post-9/15 Gains Were Attributable to National TV and CTV
When national TV resumed on September 29, with Phoenix local TV fully off, sessions increased across markets. Phoenix rose, but Tucson rose too. The gap narrowed, and Phoenix no longer over-indexed at levels seen during local TV flights. Lift was present, but flatter and more evenly distributed.
National TV supported demand, but it did not recreate the incremental impact of local market investment.
CTV Maintained Demand, With Limited Differentiation
The national CTV flight (11/3-12/22) followed a similar pattern. Sessions stayed elevated versus pre-TV baselines, but lift was lower than during local TV. Phoenix and Tucson tracked closely throughout the period, suggesting limited market-specific impact. CTV helped maintain demand, but did not materially change relative market performance.
Implications for Media Investment
The analysis points to clear roles for each channel:
Local TV
- Consistently drove incremental website demand
- Produced repeatable lift across multiple flight periods
- Performed best when evaluated against a comparable control market
National TV and CTV
- Supported baseline demand across markets
- Delivered broader, less differentiated lift
- Functioned most effectively as supporting layers rather than primary growth drivers
Local TV in Phoenix produced measurable, causal lift in website traffic. That lift faded quickly once media support ended and did not persist through national TV or CTV alone.
Here's my take: For teams focused on incremental growth, local TV can be justified when evaluated against clear control benchmarks. National TV and CTV remain valuable, but as complements to local market investment.
Want to talk strategy? Reach out to Ian Mackie.
