Why do sales and marketing keep drifting apart anyway?

You got both teams to nod at the same plan. That is not the hard part, and you know it. The hard part is what happens after the meeting ends, when each team walks back into its own room and its own goals. No one lies on purpose. Marketing chases its numbers. Sales chases its own. Weeks pass. The drift is invisible until a deal stalls in the gap between them, and by then you are doing forensics instead of prevention. This is not a trust problem. It is not a culture problem. It is a rhythm problem. You have no recurring moment where the drift would be seen before it costs you something. Build that moment, or stop pretending the alignment holds.