Best Agencies for Incremental Sales Lift via Omnichannel (2026)

This guide covers what separates a measurement-led agency from one that just reports platform numbers, how to run the evaluation, and which agencies are equipped to deliver real incremental lift.

• 85% of marketers say they can measure ROI holistically, only 32% actually do it across all channels (Nielsen Marketing ROI Blueprint, October 2025)

• 52% of US brand and agency marketers now use incrementality testing (eMarketer/TransUnion, July 2025)

• Independent geo-test benchmarks put the gap between platform-reported ROAS and true incremental ROAS at 2-3x on average, and 5-10x on branded search and retargeting (Stella, 225 DTC geo tests, 2026)

• Incremental lift measurement requires a control group, matched market selection, and an agency willing to share numbers that may be lower than platform-reported ones

What Incremental Sales Lift Actually Means

Most agencies talk about ROAS. Fewer talk about incrementality. The gap between the two is where marketing budgets get wasted.

ROAS measures revenue attributed to a channel over spend. Incrementality measures what would have happened without the ad. The delta is what your campaign actually caused.

Here is why this matters: a retargeting campaign showing 8x ROAS might be doing almost nothing incrementally. The people it is reaching were already going to buy. Meta's default attribution window includes view-through conversions, which inflate ROAS further. An account can look like it is performing well while its actual incremental return is close to break-even.

The agencies worth hiring for omnichannel growth understand this. They build measurement setups that separate causal lift from correlation, then optimize spend around the channels doing real work.

How Most Omnichannel Campaigns Get Measurement Wrong

Nielsen's 2025 Marketing ROI Blueprint found that 85% of marketers feel confident about their ability to measure ROI holistically. Only 32% actually do it across all media channels (Nielsen). That 53-point gap is not a knowledge problem. It is a structural one.

Most omnichannel measurement fails for three reasons.

Channel isolation. Meta reports Meta results. Google reports Google results. Neither knows what the other is doing. An account running both channels will show inflated ROAS in each because both take credit for the same conversion. Without third-party measurement, you are double-counting.

Last-touch bias. Standard attribution gives credit to the last touchpoint before conversion. In an omnichannel program, that is usually retargeting or branded search, which captures demand other channels built. Cutting low-ROAS channels while keeping retargeting intact is a pattern this model reliably produces.

No control group. Without a holdout group, there is no baseline. You cannot know whether customers who saw the campaign would have purchased anyway. Holdout testing requires geographic segmentation or audience suppression, both of which require intentional setup.

According to eMarketer and TransUnion (July 2025), 52% of US brand and agency marketers now use incrementality testing, with 36.2% planning to increase incrementality spending over the next 12 months (eMarketer). The agencies at the front of this curve have a structural advantage in how they deploy client spend.

How to Evaluate an Agency's Measurement Capabilities

Before you evaluate track records, evaluate the measurement philosophy. An agency that cannot explain how they measure incrementality cannot prove they are delivering it.

The clearest signal of a measurement-capable agency: they will tell you upfront that your in-platform ROAS is probably inflated and explain how they will help you find the real number.

The Best Agencies for Incremental Sales Lift via Omnichannel (2026)

This list focuses on agencies that have built measurement capabilities into their core service, not as an add-on. For each, the summary covers measurement approach, ideal client profile, and honest limitations.

Jetfuel

Best for: DTC and CPG brands doing $2M or more in revenue that need paid media and conversion optimization run together under a measurement-led framework.

We run incrementality testing as standard practice. Our approach separates in-platform attribution from third-party multi-touch data, and we structure geo-based holdout experiments on accounts with enough conversion volume to produce statistically valid results.

Where we specifically differentiate: we connect paid performance to on-site conversion rates in the same reporting loop. Optimizing spend toward a channel makes no sense if the landing page is the actual bottleneck. We address both sides in the same engagement.

Our attribution stack includes Northbeam and Triple Whale as the measurement layer, combined with Meta and Google's native incrementality experiments and matched-market (ads-on versus ads-off) holdout tests where an account has the volume to support them. We do not quote a single headline lift figure here, because incremental lift is account-specific: independent geo-test benchmarks put the gap between platform-reported ROAS and true incremental ROAS at 2-3x on average (Stella, 2026). Finding your account's real number is the job.

Limitation: We push back on aggressive spend scaling before the incrementality baseline is established. Brands looking to scale fast without measurement infrastructure are not our best fit.

Common Thread Collective

Best for: DTC brands with established Meta spend who want a rigorous geo holdout framework and are willing to invest time in the testing phase.

Common Thread runs a documented incrementality testing practice with a specific geo holdout methodology (Common Thread Collective). They use matched market pairs, suppress ads in control geos, and measure the purchase rate delta. Publishing methodology publicly is more than most agencies do.

Their scope is primarily paid media. CRO and retention sit outside their core offering, so the incrementality data informs paid decisions but full omnichannel coordination depends on your internal team or other partners.

QRY

Best for: DTC brands with $5M or more in revenue that need a sophisticated attribution stack built and managed alongside paid channel execution.

QRY has published thinking on multi-platform attribution tool evaluation, covering the tradeoffs between Northbeam, Rockerbox, and Triple Whale for different account types (QRY). That level of public attribution depth signals a methodology-first approach. They are well suited for brands where the measurement infrastructure needs to be built from scratch.

Power Digital

Best for: Mid-market and enterprise brands that need full-funnel execution across paid, SEO, email, and creative with a proprietary data platform connecting all channels.

Power Digital built their own analytics platform (nova) to consolidate cross-channel data and model performance across the full funnel. Their size gives access to a broader benchmark pool than smaller agencies, useful for brands that want industry comparisons alongside their own numbers.

The tradeoff: at the enterprise end of the market, account management tends to be less hands-on at the senior level than smaller specialty shops where the strategist is also the one who built the methodology.

The Measurement Stack Behind the Numbers

Most agencies doing this well run some combination of four layers:

The mature measurement approach in 2026 uses attribution for in-flight decisions, incrementality testing to validate those decisions quarterly, and MMM to guide annual budget allocation (House of Martech). No single tool does all three jobs well. Agencies relying on one layer only are giving you an incomplete picture.

For context on what omnichannel campaigns typically cost, see our breakdown of omnichannel marketing on a budget.

Questions to Ask Before You Sign

These questions separate agencies that actually measure incrementality from the ones that use the word in sales decks.

How do you separate in-platform ROAS from incremental ROAS? A real answer describes a specific tool or methodology. A vague answer describes the general concept.

Have you run a geo holdout test? Walk me through how you set it up. Agencies that have done this describe matched market selection, suppression logistics, and test duration. Those that have not will generalize.

What happens when your incrementality number comes in lower than ROAS? The right answer involves showing the client both numbers and adjusting spend accordingly. The wrong answer avoids the question.

How do you measure lift across the full channel mix, not just per channel? Paid social incrementality in isolation does not tell you whether coordinating email plus paid plus search produces lift beyond individual channel performance.

Frequently Asked Questions About Incremental Sales Lift

For the broader agency comparison by revenue stage, see our guide on which agency is best for scaling a DTC ecommerce brand.