Under every piece of advice sits a knowledge layer of 105 principles from published research, each with the limit of what it means. Three of them, as they sit in the system.
Check the measurement before judging anything else.
A conversion counted at the wrong moment makes every judgement about your marketing worthless. We start there, and that is usually where it goes wrong.
Practice principle from the knowledge layer
Does not mean you cannot advertise without perfect measurement. It means you do not believe your numbers blindly.
Treat recommendations from Google and Meta as a sales signal.
The optimisation score in your account is a sales metric, not a report card. A recommendation goes through when the evidence supports it.
Practice principle from the knowledge layer
Does not mean those features never work. With a sound conversion signal underneath they can be perfectly good.
Growth comes mostly from new customers, not from making existing ones more loyal.
Brands of similar size have almost identical loyalty. The ones that grow, grow by reaching more people who have not bought yet.
Ehrenberg-Bass
Does not mean you may neglect existing customers, or that this holds when you already serve nearly your whole market.