Measure the business, not the store
If you sell in more than one place, judging paid media against the online store P&L alone misreads the whole business.
Over the last decade consumer brands have leaned harder on paid media to grow while expanding the number of channels they distribute through in order to reach profitability. Most still measure the return on that spend against their online store alone.
That produces a less accurate understanding of the business as a whole, and handicaps future growth. Spend that looks unprofitable against DTC revenue may be comfortably profitable once wholesale and retail are counted.
The fix is structural rather than analytical: define a combined advertising budget across channels, consolidate management of direct response, delayed response and retail spend, and amortize return across every point of distribution. That produces an incentive structure and an advertising architecture that can actually support profitable omnichannel growth.