Not all organic traffic is equal. This is an important concept to understand when you invest in content. Ahrefs traffic value is defined by the money it would take to bid on that same traffic with PPC ads. It's not the only metric you should monitor, but it's a good directional data point because if people are willing to spend money on that traffic (and that traffic is relevant to your brand/products), it's a sign that you're driving higher intent visitors and are giving yourself a good chance to turn them into a customer.