Why it matters
Heatmaps answer the "why" behind weak numbers: the button nobody notices, the fake-looking image people ignore, the crucial content below where scrolling stops, the element everyone clicks that isn't a link. They turn redesign debates into observations.
How it works
A lightweight script aggregates interactions across many visits into click, movement and scroll maps; session recordings usually come bundled. Read them per device (mobile and desktop behave differently) and per traffic source when pages serve several audiences.
What to do about it
Run one on your highest-stakes page for two weeks. The scroll map alone (showing what share of visitors ever see each section) usually reorders the page all by itself.
