I buy and sell many items on Craigslist and ebay. Ebay, I have found to be much easier dealing with people, its more of a contract. Although Craigslist doesnt usually involve shipping, it also doesnt involve a contract. So when i post something for sale on CL, i get 30 emails saying "is this still available" (sometimes even 20 minutes after i post it) then when i reply "yes" and tell them my area and time of availability, they never respond. Or sometimes they do and say they are coming and never show up or when they get there, they try to haggle the price or decide they dont want it.
In fact, recently we got a new dining room set and i tried to sell our old one online, the guy came to buy it, then when he got there, made a sob story about how the table was too small (the dimensions were in the ad!) and his all of his kids couldnt fit around it. I sold him just the chairs for $100 (instead of the set for $200) cause i felt bad for the dude. 3 weeks later, my chairs are around another dining room table on CL for $600!!!!
anyway, I prefer ebay cause it somewhat eliminates people sheer stupidity, ignorance and flat out inconsideration for other peoples time and money.