A position says what would prove it wrong. Test each on your own business.

1. Contribution margin per order is the first number, not revenue or ROAS.Wrong if your best-ROAS products and your best-contribution products are the same list.
   One Order’s P&L
2. Four numbers run a DTC business: new customers, what each cost, what the first order left, and how many come back.Wrong if you can explain last quarter’s profit change without any of them.
   Four Numbers Run the Business
3. Manage to payback in months, not lifetime value.Wrong if your cash position has never constrained how much you could spend on acquisition.
   Payback Beats Lifetime Value
4. Most growth comes from more buyers, not more loyal ones.Wrong if your revenue growth last year came mostly from existing customers buying more often, not from new customers.
   Reach Beats Loyalty
5. A creative brief has four parts: offer, angle, audience and format. Most briefs only have format.Wrong if your winning ads can’t be told apart from your losers by angle or audience.
   The Brief
6. Platform-reported results are a claim, not a measurement.Wrong if a holdout test on your biggest channel finds the lift the platform reported.
   What the Platform Says You Caused
7. The cheapest growth is at checkout, not in the ad account.Wrong if your checkout completion rate is already within a few points of the best in your category.
   The Page and the Checkout
8. A list that isn’t growing is shrinking, because it decays every month.Wrong if your count of subscribers who engaged in the last 90 days is flat or rising with no new sign-ups.
   The List Is the Asset
9. Flows are the floor. Campaigns are the ceiling. Build the floor first.Wrong if a brand with no welcome, cart and post-purchase flows makes more per subscriber than one with them.
   The Six Flows
10. Deliverability is a number you manage weekly, not a setting you fix once.Wrong if your spam complaint rate has never moved when you changed who you send to.
    Get to the Inbox
11. Judge everything on cohorts, not calendar months.Wrong if your calendar-month reports and your cohort reports rank your programs the same way.
    Cohorts, Not Calendars
12. A test without a written hypothesis teaches nothing, even when it wins.Wrong if your team can name what it learned from its last ten tests without looking them up.
    Tests That Teach