The only reason craigslist isn't more popular is there are not enough people using it, and enough organization on the site yet.
I think CraigsList is a very popular site. They have more then million visitors a day. When it comes to choose between those two; main difference is paid posting and free posting. CraigsList offer free postings for most places. However Ebay has more quality ads.
I don't use either of them a lot. The couple times I've visited Craigslist, it is so cluttered, confusing and just nasty looking. I've used ebay when I was looking for wierd things, like little plastic camels for my sons diarama, you can find almost anything on Ebay but you have to realize that you might be throwing your money into a black hole because there are a lot of scammers.
Ebays fees are getting to be too much. Craigslist isn't as attractive a site, but that is the cool thing about it. Plain and simple. i am just scared that I am gonna meet up with some dude that sold me a 360. instead of exchanging cash he will steal my money and touch my apron spots. treat me like a hooker on GTA.
i love craigslist, i could buy anything anytime.. same day purchase or same day for selling on meetups.. its popular and more convientant.. just need make sure who you dealing with