yeah you can try, for print/OTT the most common way to estimate lift is with DMA segmentation, compare lift in the DMA's which saw the ad versus the DMA's which didn't. but how do you pick the right DMA's to pair, etc. it's hard and i think most people don't do it right; again, it requires very large n to do correctly, which requires very large budgets.

mcdonalds is actually one of the savvier players here, they know that it's hard to quantify brand advertising if you only go off in-store purchases, so they spent very heavily to promote their app and develop a consumer-brand relationship there. now, if you see a mcdonalds ad on youtube, they can (try to) match your youtube ad impression to a purchase done through the app / credit card / other PII.