Everything you should know about why eBay will get pwned with it's Kijiji vs Craigslist play has already been said...by Jim Buckmaster: "...Craigslist’s chief executive, Jim Buckmaster, said, “One of the beauties of viewing our world through public service goggles is that there is no need to worry about what other companies are doing.
“Many companies offer classifieds, but since we don’t concern ourselves with considerations such as market share or revenue maximization, we don’t think of them as competition, or as a challenge to Craigslist."
Beautiful stuff - because it's where massively dominant strategy and enormous social gains must necessarily intersect in the post-network economy.
Which is exactly what core focused players will forever be unable to understand - Jim has it exactly right when he notes that it's not, any longer, focusing on competitors or the "market" that leads firms to deep, durable, powerful value creation.