Why Good Measurement Starts Outside the Platform
Source published: March 24, 2026
Published by Cardinal Digital Marketing, which sells healthcare performance marketing services. Not an endorsement by Healthcare Growth Strategies, Paul Gruensfelder or his employer. Sample/method: podcast interview, Cardinal host Lauren Leone with Alex Kemp, Sr. Director of Analytics; illustrative examples, no data sample stated. Figures are the vendor’s and were not independently verified. Editorial standards
Good measurement starts with a source of truth outside the ad platforms, usually a CRM that records every lead and its stage, according to Cardinal Digital Marketing’s Ignite podcast. Alex Kemp, Cardinal’s senior director of analytics, warns that a blended CPA can hide inefficient spend: if an extra $10,000 brings in 10 patients, the marginal CPA is $1,000 even when the blended figure stays under a $300 target. He suggests adding a delta column to month-over-month reports, dividing the change in cost by the change in new patients. Platforms can also over-count, for example 2,000 reported conversions against 1,500 actual new patients, often from view-through credit. Kemp recommends triangulating last-click attribution, media mix modeling and incrementality tests.
Multi-site groups often scale paid media by watching platform-reported CPA, which can reward spend that adds few real patients. Tracking marginal CPA, treating view-through conversions as assists and reconciling platform totals against new patients in the CRM are steps a marketing team can start this month without new tools.
While we aim to share useful and relevant resources, we can’t guarantee the accuracy of all third-party content. Always apply professional judgment when acting on information from external sources.
What is the blended CPA trap in healthcare marketing?
A blended cost per acquisition can look on target while extra spend brings in patients at a much higher marginal cost. Cardinal’s example: $10,000 of added spend yielding 10 patients is a $1,000 marginal CPA.
Why do ad platforms report more conversions than new patients?
View-through conversions, especially on Meta and DSPs, and search conversions that followed earlier impressions can inflate platform totals. Cardinal suggests fitting attribution windows to the business and counting view-throughs as assists.
What measurement model does Cardinal recommend?
Triangulation: last-click attribution from a CRM source of truth, media mix modeling for modeled channel contribution, and incrementality tests such as geo-lift or holdouts to calibrate the model.