Streaming took 44.8% of US TV viewing time in May 2025. Broadcast and cable, added together, came to 44.2%, a smaller share of the same viewing hours. The side channel is the main one now. 

Yet most brands still treat CTV advertising, meaning ads inside streaming TV apps, as an add-on to a linear buy or a test line in a performance budget. That planning order is expensive. Geo-lift tests keep showing that CTV exposure raises paid search conversion rates and cuts cost per conversion, but last-click reports hand the credit to search, so CTV gets funded like an experiment and judged like one.

CTV advertising is the anchor of an open-internet media plan

CTV advertising is the addressable spine of an open-internet plan. Connected TV is any internet-delivered streaming video watched on a television screen. It identifies households rather than dayparts, so it sets the targeting, frequency, and measurement rules that search, social, display, and audio then inherit.

Advertisers already say this out loud. In the IAB's 2025 survey, 68% of US advertisers listed CTV as the most necessary channel for a media plan, ahead of social video. The budget process hasn't caught up. CTV still gets planned inside the TV envelope, which caps it at whatever linear was already spending and treats streaming as a substitute for lost broadcast reach.

That frame damages the numbers. When CTV sits in the TV line, it gets graded on TV metrics such as reach, frequency, and cost per thousand. Those metrics can't see what the channel does downstream.

The measurement mismatch is a budget problem

Exposed households search more, click paid ads more, and convert at higher rates. In one analysis, CTV exposure drove an 8.5% increase in paid social conversions against control groups. Last-click reporting hands that credit to social. CTV shows up as expensive reach, and the next planning cycle trims it.

Agility's work with one national outdoor retailer showed the same shape at larger scale: 138% paid search conversion lift, 88% Bing conversion lift, and 2.6x Meta ROAS from cross-channel halo. But none of that appears in a GRP report.

The fix is structural. Brands that compound with CTV changed the order of operations: CTV gets planned first, measured with a brand lift design a CFO will accept, and funded from the channels it lifts. Budget architecture separates a program from a pilot.

The money already moved. The planning order did not.

The supply side reorganized faster than the buying process did. Streaming already owns the larger share of US TV time, and US digital video ad spend jumped 18% in 2024 to reach $64 billion, surpassing linear TV ad spend for the first time. Dollars followed attention at the category level. Inside most brands, the calendar didn't move.

In many organizations, search and social budgets get locked first, because they've got last year's numbers and a clean efficiency story. Then someone asks what's left for video. CTV advertising inherits leftover dollars and leftover flight windows. That caps share of voice before a single spot runs.

Bolt-on budgets cannot clear the share-of-voice threshold

The math isn't friendly. Growing market share by roughly one point a year takes about 20 points of excess share of voice, sustained. A residual CTV line doesn't come close. It buys three weeks in Q4, hits a household four times, and produces a reach curve that looks like a rounding error next to the category leader.

So the change is sequencing, not spending. Set CTV weight first, then size search and social around it. CTV is an input that changes what performance channels cost.

The honest counter-case

Short flights don't produce share effects, and pretending otherwise burns credibility with a CFO. Only about 3% of campaigns running six months or less achieve large market-share gains, versus 38% for campaigns running three or more years. Under roughly six continuous months, expect downstream lift in paid search and paid conversion efficiency, not a share move. Plan the duration you can actually fund. Then commit to it.

What changes downstream when CTV runs as the anchor

When CTV advertising anchors the plan, most of its return shows up somewhere else. Exposed households search for the brand more often, click paid listings more often, and buy at higher rates. The CTV line's contribution lands in dashboards owned by the search team, the social team, and the site.

Geo-lift tests make that visible. In one market test, adding CTV in a new DMA lifted PPC and LSA conversion rates by 82% while cost-per-conversion decreased by 2%. LSAs are Google's local service ads. In the matched control market with no CTV, conversion rates increased 34%, but cost per conversion rose 20%. Same brand, same quarter, one variable.

Last-click hides the halo by design

Last-click reporting credits the final touch before the sale. About 30% of paid-search conversions are actually attributable to brand and upper-funnel efforts, and last-click attribution can inflate perceived results 2-10x. So the search team books a win that CTV created, and the CTV line shows only its cost. That's a bookkeeping failure, and it repeats every planning cycle until someone changes the scorecard.

Give CTV a downstream KPI

Delivery metrics alone keep the channel underfunded. Reach, frequency, and completion rate describe what ran. They say nothing about what changed. Add at least one downstream number to the CTV scorecard and review it monthly:

• Cost per net-new site visit

• Search conversion-rate delta between exposed and holdout geos

• Blended CAC across the full portfolio, not per channel

Cost pressure makes this urgent. Average Google Ads CPC climbed to $5.26, a 12.9% year-over-year rise, and Meta's average CPM in Q1 2025 reached $10.88, up 19.2%. Most brands respond by raising bids. The cheaper lever sits upstream: lifting the conversion rate on traffic you already buy beats paying more for the same traffic, which is a buying decision more than a bidding one. Measure the channel where its money lands.

The three decisions that separate a CTV program from a CTV test

Three choices decide whether CTV advertising compounds or stalls: how you set supply floors, how you flight the budget, and how much creative variety you fund. Brands that get these right run programs. Brands that skip them run tests that get canceled in the next budget cycle.

Supply floors before price negotiation

Set inventory quality floors first, then talk CPM. About 25% of open-web programmatic spend is waste, and only 36 cents of every dollar entering a DSP reaches the consumer. Cheap CTV inventory usually means unknown apps and mismatched screens. Discipline on supply beats a better rate card.

Fund continuous presence

Over half of ad profits appear 13 or more weeks after airing, and short campaigns are 4.6x less effective at driving market-share growth. A three-week burst looks good in the quarterly deck. It does almost nothing to the base, so if you must, fund fewer weeks at higher weight, but keep the lights on.

Creative weight matches targeting weight

Creative quality drives 49% of incremental sales. Targeting drives 11%. A plan with perfect audience work and one recycled linear spot has a hard ceiling, which is why shipping creative variants at volume matters more than another data segment.

One pairing decision sits underneath all four. TV plus online video drives +3.1% annual market-share growth, versus 2.6% for TV alone, so CTV performs better inside a video portfolio than isolated in its own line. One documented deployment cut acquisition cost 45% and raised lead volume 14% by integrating CTV into the existing video and search mix. Decide all four before the first insertion order, not after the first flat report.

How to fund CTV without asking the CFO for new money

The funding case is a reallocation case, not a budget increase. Most large advertisers already run a brand-to-performance split near 31.2% brand and 68.8% performance, while the same marketers describe roughly half-and-half as ideal. That gap is a plan defect, and a CFO can read it in one slide. You're asking to move money that's sitting in the wrong place.

The dollar math supports the move. Rebalancing from performance-only spending toward an integrated brand-plus-performance mix lifts total revenue returns 25% to 100%, with a median uplift near 90%. Airbnb makes the cleanest precedent. It cut roughly $500 million from performance marketing, shifted the money to brand, and grew revenue 24% year over year. Traffic held. Margins improved.

Pre-commit the read before the first impression

Most CTV programs die because the renewal conversation becomes a debate about faith. Write the test down first. Define the holdout markets, flight length, and 2 or 3 downstream KPIs before anything runs. Then the renewal meeting is a data review.

In April 2025, Nielsen's Gauge report showed streaming at 44.3% of total TV viewing time. That share of viewing is what gives the reallocation its reason, and the trend hasn't reversed since. Funding CTV advertising from the linear envelope alone caps it at a shrinking base.

Doing nothing carries its own price

Standing still is a decision with a bill attached. Brands that go dark give up future revenue for every quarter they stay dark, and companies that cut brand marketing needed about $1.85 in new spend to recover every $1 they saved. Put that number next to the reallocation request. Not what CTV advertising costs, but what a flat plan costs over four quarters.

How Agility plans CTV as the spine of an open-internet buy

Agility builds media plans in that order. CTV weight gets set first. Precision persona targeting resolves one household across CTV, display, audio, and DOOH, drawing on 1,000+ third-party data sources, and builds those audiences automatically instead of hand-assembling them inside each platform. That household then carries one frequency budget across the entire plan, instead of four platforms each counting the same viewer twice.

Media buying sets supply floors before price. Creative funds variants at the weight the targeting deserves. Measurement science closes it with a holdout, not a delivery report.

See what precision brand advertising looks like for your brand at agilityads.com/test-precision-advertising.