BBC: lost 10% of users for every additional second the site took to load

Quote (web.dev/learn/performance, 2024):

"BBC lost an additional 10% of users for every additional second the site took to load."

Source: https://web.dev/learn/performance/why-speed-matters

Confidence: Verified.

The cleanest "speed loss curve" stat in the public literature. Loses 10% per additional second is roughly linear over the relevant range (1-5 seconds), which makes it a useful "rough calculator" for client conversations: "if your LCP is 4 seconds and the median is 2.5, you're losing roughly 15% of users to that 1.5-second penalty."