Ask HN: How did you turn your failed business model into a successful venture?

I started with flipping gadgets, but failed at first to make a substantial income. It was hard to make ends meet...<p>At first we bought devices from dealers and stores who got them in exchange.<p>But thereafter, my profit increased 5-6x after I started a business model which cut down all middlemen and bought gadgets directly from consumers. There have been some issues like stolen devices and as such, but profits soared!<p>Want to know other hackers turned a failed business to something successful.