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...

At first we bought devices from dealers and stores who got them in exchange.

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!

Want to know other hackers turned a failed business to something successful.