That business model of Live Nation has long fascinated me. And their tickets are pricey. At one point they were giving rise to monopoly accusations. But people are paying.
GroupOn reminds me of Live Nation. GroupOn has not come up with code that has confounded the minds of the Mark Zuckerbergs and Sergey Brins of the world. Their technology is quite simple. You could argue their business model is also equally simple, and hence the hundreds of copycats. But what I notice most is they took that step to go offline. They employ thousands of salespeople who go knock on the doors of local merchants. I find that proposition exciting.