In an excellent post about Meg Whitman's retirement, David Galbraith succinctly summarizes the most important thing about eBay's potential:
Ebay is all about Green, the biggest angle any company can have, currently, and yet it has ignored this. As the largest marketplace for second hand goods, it is the worlds largest recycler.
Similarly, despite my frustrations as an iPod Touch owner that Apple is charging $20 for an update to the device, I am heartened that their revenue model may be evolving, even if just in a tiny way, from planned obsolescence. They claim their devices are more green because of reduced PCBs in the circuit boards, but the best thing they could do is to make their revenue model rely on throwing away software, instead of throwing away hardware. It's been said there are hundreds of millions of cell phones that live in drawers, and I suspect that the 100 million iPods that have been sold were sold to perhaps 30 million households. That's a lot of costly devices sitting in disuse. Software subscriptions are a much less planet-clogging option than hardware subscriptions for companies which offer both.