The 'Feature Tax': Why SSO and MFA Cost You More Despite Near-Zero Marginal Cost

A growing critique in the software industry targets authentication vendors that charge premium prices for features like Single Sign-On (SSO) and Multi-Factor Authentication (MFA), despite these costing providers almost nothing to deliver. The site sso.tax was created specifically to publicly track vendors that lock SSO — a two-decade-old standard — behind expensive enterprise tiers. Critics draw a sharp distinction between charging for actual resource consumption versus charging merely for permission to enable an already-built feature. Common practices cited include billing separately for SSO, SCIM provisioning, and MFA as distinct per-seat products, or imposing high annual entry fees before a single user is authenticated. The article argues this model, often dressed up as 'value-based pricing', is in reality a toll on infrastructure that has already been built and paid for.