To the people that are confused by Bitcoin, just think of it like paying for gold in World of WarCraft. It's not a perfect analogy, but it's kind of similar as it's a digital good that's being assigned a value by "the market". Diablo III might even be a better example since there was a legit way to purchase gold in that game and the value fluctuated. Based on that monetary value, someone could conceivably trade me a real world item based on the assumption that the digital currency that I gave him would be able to net him real world currency.
I've always been a bit wary to consider these things a ponzi scheme because the idea of a ponzi scheme is to try and recruit others and to get them to do the same to create a pyramid with a pay-up scheme. The early miners certainly earned more but that's because they didn't have as much competition. More people may mean more coins found (bitcoin mining is sort of like a hashing scavenger hunt), but then the difficulty will go up. I remember back when I used to mine bitcoins, the difficulty nearly doubled on me, and I did see about a 50% reduction in the number of coins that I saw.
In other words, ponzi schemes rely on popularity to fuel the earlier people where bitcoin relies on people sitting on coins before it gets popular.
I've always been a bit wary to consider these things a ponzi scheme because the idea of a ponzi scheme is to try and recruit others and to get them to do the same to create a pyramid with a pay-up scheme. The early miners certainly earned more but that's because they didn't have as much competition. More people may mean more coins found (bitcoin mining is sort of like a hashing scavenger hunt), but then the difficulty will go up. I remember back when I used to mine bitcoins, the difficulty nearly doubled on me, and I did see about a 50% reduction in the number of coins that I saw.
In other words, ponzi schemes rely on popularity to fuel the earlier people where bitcoin relies on people sitting on coins before it gets popular.