This code will log `1, 2, 3...` incrementing each second. It demonstrates a practical use case for arrow functions—maintaining the correct `this` context in callbacks. In the `increment` method (a regular function), `this` refers to the `counter` object. The arrow function inside `setInterval` inherits this same `this` value because arrow functions don't have their own `this` binding. Each second, the callback executes, incrementing and logging the counter's `count` property. If a regular function were used instead (`setInterval(function() { console.log(++this.count); }, 1000)`), `this` inside that function would refer to the global object (or be `undefined` in strict mode), not the counter object. This would cause `this.count` to be `NaN` or throw an error. Before arrow functions, developers had to use workarounds like `var self = this` or `.bind(this)` to solve this problem. This example shows why arrow functions are particularly valuable for callbacks, event handlers, and other scenarios where preserving the lexical `this` is important.