To buy things on
Craigslist, then resell them for a profit.
The purchase of items in one market for immediate
resale on another market in order to profit from a price
discrepancy.
I wasted much of my time playing World of Warcraft, I liked
to slay dragons and fight zombies as much as
the next guy. But what I really enjoyed was shopping at the in-game auction house. When you had stuff you didn't want, you could sell it to other players through
auctions. I was practicing Craigslist arbitrage. And soon my lowly little wizard had a fortune of hundreds of gold pieces.