[mrfredward]

And the underlying economic reason for Apple's shares to go up when it wasn't paying a dividend is that as Apple accumulated cash and became more profitable, the chances that it would pay a fat dividend someday (even if not in the near future) kept going up.

If companies didn't ever pay a dividend or buyback shares, the whole thing would be a ponzi scheme. The company takes money in an IPO, and then investors shuffle money among themselves to make it look like they have a profit, but it would collapse if people want to cash out. When companies eventually distribute profit to investors however, it becomes possible for cash to leave the system without all the paper value disappearing into thin air.