How Mather Economics’ Subscription Proficiency Index (SPI) Helps Publishers Increase Engagement & ARPU

At the INMA Subscription Summit in March, I attended a seminar by Mather Economics, where they introduced their SPI methodology. This framework is designed to boost publisher revenues and APRU.

In today’s rapidly evolving media landscape, digital subscriptions have become the cornerstone of sustainable growth for news publishers. Yet, while many organisations are investing heavily in digital transformation, far fewer have a clear, consistent way to measure the effectiveness of their efforts across the full subscriber journey.

Mather Economics’ Subscription Proficiency Index (SPI) — a strategic performance framework designed specifically for publishers. It offers a powerful, data-driven approach to diagnosing, tracking and optimising subscription performance over time.

What Exactly Is the SPI?

The Subscription Proficiency Index (SPI) is not a vanity metric or static snapshot. It’s a comprehensive scoring system that evaluates a publisher’s proficiency across the most critical aspects of digital subscription growth, assigning a performance score from 0 to 100.

The score is calculated using six key variables, each weighted by its importance to long-term subscription health:

1. Audienc…