Craigslist has done a far more important job in this domain because it is focused locally where tastes are somewhat homogeneous and freight costs are low or negligible.
If one is an environmentalist, then recognition is due to these new businesses for keeping vast tonnage out of landfills and keeping vast amount of resources from being used to create new products.
In fact these two companies probably do more for the environment than the entire environmental movement in its history.
I feel compelled to make an estimate of how big the recycling garage sale market is that has been created by these two businesses.
Total reported retail sales excluding automobiles ( which have had a secondary market from the beginning) and food is roughly $1.5 trillion. Based on my wildest guesses from observing my friends, 10% of goods and services at retail are exchanged on Craigslist and eBay.
That means that $150 billion is being saved annually by people using second hand resources. I would value that at $0.5 trillion in new product pricing.
These two companies save Americans a great deal of money and increase our effective incomes significantly.