Most UK ecommerce brands didn't choose to run six different data sources. They just ended up there. A few years ago it was Shopify and maybe a spreadsheet. Now it's Shopify, Amazon UK, Meta, Google Ads, GA4, and whatever ad platform tested well last quarter. This UK ecommerce analytics market guide 2025 exists because that shift broke the old way of doing reporting: pulling a few exports on a Friday afternoon and eyeballing the numbers.