The article says,
"Craigslist allows anyone to post ads for almost anything they want to sell, without charging them a cent. Buyers don't pay either. People find jobs, rooms to rent, pets, furniture and clothes, as well as lovers, on Craigslist. The effect of the network on our society is hard to gauge, but it's difficult to find anyone in the tech sector or in the nation's biggest cities that hasn't unloaded an old couch or found a roommate on the site."
Craigslist is great. Check out the Best of Craig's List, for some humorous postings. I know it's a huge enterprise but by reading craig's blog I get the feeling it's a community. Awhile ago I ran across some pictures he had posted of his grandkids that were really cute - gotta love a guy who love's his kids and grandkids.
If you happen to be a student on vacation, Craigslist can be a good resource for finding work - either a full time temporary position or if you like more flexibility and are able bodied, by placing an ad to help people move, garden, do construction...that sort of thing.
Speaking of what you can learn on Craigslist, there's an interesting old post on the Best of Craigs List that speaks to people who would like to hire someone really really cheap, and the impact that has on our society. It's a post about someone who wanted to hire a painter to paint the interior of a house for $800. The job might be bid at around $3000, but the poster is looking for some poor soul who would be willing to do the work for about 1/4 of what it should pay.
There are many reasons why super-good deals on labor are not good for society or the individuals forced (or willing) to do work for less than what it's worth. You can read the comments at best of craigslist : Re: Painting & Wall Patching "Gig"= CHEAP BASTARD ! ! !