CASH-ADJUSTED FUNNEL MODELING IN MVA, PERSONAL INJURY, AND MASS TORT LEGAL ADVERTISING: AN EMPIRICAL ANALYSIS OF COST PROPAGATION AND REWARD-BASED ROI (JUNE 2023 – OCTOBER 2025) IN SOCIAL MEDIA ADVERTISING (GOOGLE AND META)

Abstract

This empirical paper extends prior work on stochastic funnel-cost modeling by incorporating a points-based rebate mechanism—a common feature in legal advertising spend when charged to business credit systems. Using data from a U.S. Facebook Ads account (June 2023–October 2025) with total spend of $1.105 million, this study quantifies how funnel entropy interacts with ad-auction economics in the Motor Vehicle Accident (MVA), Personal Injury (PI), and Mass Tort verticals.

Observed metrics include CPM = $28.30, CPC = $1.55, CTR = 1.83%, and CPL ≈ $300. Modeling the multi-stage funnel—Impression → Click → Lead → MQL → SQL → Retainer → Won Case—yields an expected Cost per Retainer (CPR) = $1,939.5 and Cost per Won Case (CPW) = $2,585.

A novel variable is introduced, representing the reward-based effective rebate (e.g., Amex 4× points on marketing spend, with real redemption data: 90k points ≈ $6,000 return ticket USA–Europe). On $1.105M spend, this equates to ≈4.5M points, ~50 business-class tickets, and $300,000 equivalent value, or ≈27% cashback. When incorporated, the effective CPR drops to $1,415 and ROI rises from 29% to 77%.