This example demonstrates a text counter that smoothly transitions from one numeric value to another, appending the unit " Kunden" (German for "customers"). It shows the counter animating from 33 to 8,748.89 over 2.5 seconds using a tween. The code defines a custom German locale with `d3.formatDefaultLocale`, using a comma as the decimal separator and a period for thousands grouping, and applies the format via `localeGerman.format(",.2f")`. The transition uses `d3.select` to bind the initial data, then employs `transition.tween` within an `on("start")` handler, leveraging `d3.interpolateNumber` to compute intermediate values. The rendering targets an `h1` element, updating its text content on each tick of the tween.