Google Analytics 4 is free and covers session and event data well — but it has structural gaps for ecommerce that show up immediately. Here is the setup walkthrough, the reports that matter, and which gaps you need third-party tools to fill.

Customer retention rate = ((End customers - New customers) / Start customers) × 100. Here is the formula in detail, e-commerce benchmarks by vertical, the three calculation mistakes that distort the number, and how to use cohort retention instead for serious analysis.

Most churn reduction advice does not move the number. Here are the 5 interventions that actually do, ranked by impact and time-to-result — from smart dunning (30-day win) to VIP loyalty programs (12-month compounder).

Polar Analytics covers attribution and dashboards at an accessible price — but it stops at reporting and lacks execution, retention, and AI recommendations. Here are the 7 best alternatives in 2026 ranked by where Polar falls short.

Predictive analytics for ecommerce in 2026: predictive LTV, churn prediction, demand forecasting, and price optimization. Here are the techniques that actually work, the ones that overpromise, and the tools that deliver each.