A custom demo feels productive, but it can become unpaid work if the prospect has not named a problem they want to solve. Before designing, ask three questions: What is the website failing to do now? What does that failure cost in enquiries, trust, or staff time? Who can approve a change if the demo works? If those answers are unclear, build a quick teardown instead of a full mock-up. In fact, the best demo proves one business improvement. It does not prove how much free work you can do. What do you qualify before opening your design tool?