Views, clicks, and click-through rate per box — counted in this browser. The box people pick most tells you what the audience actually wants; move it to the top. Cross-device clicks are covered by the UTM tags on every outbound link (utm_source=grid, utm_medium=grid name, utm_campaign=box).
No data yet? Open a grid page first — a view is counted on every load, a click on every box picked. Counts live in this browser's local storage only; clearing browser data clears them. That is the $0 trade: real per-visitor counts with no backend, no cookies, no spend.