Marketing-mix coherence: measure interactions that create or destroy value.
Answer:
Coherence is not an impression of alignment or an average of four scores. It describes how one decision changes another decision’s effectiveness or cost. A premium price can finance distinctive service and reinforce quality proof; it can also be contradicted by permanent promotion or by a channel unable to deliver that service. The unit of analysis is the directed interaction: which choice influences which other one, through what mechanism, with what value and above which threshold.
Method and decision:
Define concrete nodes—offer format, price corridor, sales channel, service level, media role and proof—rather than abstract categories. For each critical pair, state direction, mechanism, measure and threshold; classify it as synergy, dependency, substitution, constraint or conflict. Calculate each decision’s own contribution, then add identified interaction effects separately in low, central and stress scenarios without double-counting sales. Turn critical links into deployment conditions. Retain the mix whose critical interactions remain economically positive and operationally deliverable in the selected scenarios.
Worked example:
A premium offer adds €140 in price and €45 in service cost. Direct sales expect 1,800 customers with 85% compliance. A marketplace expects 2,200 customers, but charges €62 commission, achieves only 58% service compliance and transfers 30% of sales that would have been direct. Direct premium contribution is 140 − 45 = €95 per customer; marketplace contribution before transfer is 140 − 45 − 62 = €33. Margin lost on 660 transferred direct sales is 660 × (95 − 33) = €40,920. Non-compliance reduces estimated repurchase by 12 points, or 2,200 × 12% × €165 future value = €43,560. Net channel-service conflict is −€84,480. Volume does not offset the conflict: retain the premium offer in direct sales while marketplace compliance is below 80%, or create a distinct service version.
Limits:
Multiple interactions can be difficult to identify separately. Future value and brand effects are highly uncertain. A graph that is too dense becomes unreadable, so decision links must be prioritised.