Most DTC brands are making million-dollar channel decisions based on attribution data that's fundamentally wrong. Olivia Kory — CSO of Haus and the incrementality expert Brett references on stage more than almost anyone — breaks down what it actually takes to know if your ads are working. Spoiler: if you've been writing off YouTube based on MTA, you owe yourself a retest. Inside the episode: Why YouTube's true ROAS is 3.4X what the platform reports — and how Haus's 190-test study across 74 brands proved it (plus why your D2C numbers alone are only half the picture)The right time to start incrementality testing — it's not when you're huge, it's when your business gets complicated enough that turning off ads won't give you a clean answerHow StockX went from barely spending on YouTube to making it their #2 acquisition channel — by running geo holdout tests and acting on the resultsWhy Meta's optimization might be too good — and how brands like Jones Road are improving their iROAS by making changes that look worse in-platformThe surprise winner: AppLovin — Olivia came in skeptical of mobile game ad inventory and got data she didn't expectHaus's new DTC Basics tier — a lower-cost entry point so more brands can stop guessing which channels are actually driving growth Sponsored by OMG Commerce - go to (https://www.omgcommerce.com/contact) and request your FREE strategy session today! Chapters: [00:00] Intro clip — Olivia on treating incrementality as a report card vs. a growth tool [00:22] Introductions & background — Olivia's path from Starcom → TubeMogul → Netflix → Quibi → Sonos → Haus [06:55] What is incrementality? — The randomized controlled trial analogy; geo holdouts vs. click-based attribution [10:45] When should a brand start using incrementality? — The low-to-mid 8-figure inflection point; multi-channel complexity as the signal [15:34] Native platform lift studies (Meta & Google) — Are they worth it? Signal loss, CAPI, iOS 14.5 limitations [17:25] Geo holdout vs. user-level testing — Why Haus was "born out of the ashes of iOS 14.5" and went all-in on geo [19:37] How a Haus geo holdout test actually works — Data ingestion, experiment design, market matching, results [23:20] Actioning on incrementality data — Coaching leadership, making reallocation decisions, improving channel performance over time [26:02] How long should you run a test? — Why 2-week YouTube tests fail; 4–6 week minimums and the role of consideration cycles [27:19] Incrementality as an optimization loop, not a report card — Connor from Ridge, Cody from Jones Road Beauty, and the StockX story [30:42] Key metrics defined — iROAS, iCPA, incrementality factor, and why in-platform ROAS can mislead you [32:47] Branded search — Is it incremental? Simple Modern's 5% read, when Amazon bidding on your terms changes the math [35:57] Treatment window & post-treatment window (PTW) — How Haus structures tests for YouTube, Meta, and CTV; lagged effects explained[39:36] Consideration cycles & post-purchase surveys — Why your path-to-purchase report is probably shorter than reality [41:00] Halo effects: Amazon & retail — Why omnichannel brands that only measure D2C are understating YouTube's impact [41:58] The Haus YouTube study findings — The 3.42x incrementality factor; halo effects that doubled lift when Amazon/retail pulled in; Demand Gen vindicated [44:10] YouTube vs. Meta: how the channels differ incrementally — Meta's short payback window, the "too good at intent" problem, and why YouTube wins on halo effects [46:53] Surprises from the data — YouTube (not surprising to Olivia), AppLovin (very surprising), and why TV results swing wildly based on inventory type [50:16] The biggest levers to improve incrementality — Creative first (30–50% wins), then account structure, traffic composition, and spend level [51:46] A DemandGen campaign running on Gmail — A real audit story and why traffic composition can make a channel look broken when it isn't [53:13] Haus's new DTC Basics tier — A lower-cost entry point to measure D2C and Amazon across core ad channels [54:54] Wrap-up & where to find Olivia — Part two teased around the next Haus YouTube report Connect With Brett: LinkedIn: / thebrettcurry YouTube: / @omgcommerce Website: https://www.omgcommerce.com/ Request a Free Strategy Session: https://www.omgcommerce.com/contact Relevant Links: Olivia’s LinkedIn: /olivia-kory-50230812 Past guests on eCommerce Evolution include Ezra Firestone, Steve Chou, Drew Sanocki, Jacques Spitzer, Jeremy Horowitz, Ryan Moran, Sean Frank, Andrew Youderian, Ryan McKenzie, Joseph Wilkins, Cody Wittick, Miki Agrawal, Justin Brooke, Nish Samantray, Kurt Elster, John Parkes, Chris Mercer, Rabah Rahil, Bear Handlon, JC Hite, Frederick Vallaeys, Preston Rutherford, Anthony Mink, Bill D’Allessandro, Stephane Colleu, Jeff Oxford, Bryan Porter and more