oneounceload, it hasn't happened to you, which is nice. Google "craigslist murders," though, and you will find at least three killers - the med student who was robbing erotic masseuses, and finally killed one; the guy who was advertising for a nanny, and murdered a young woman who responded to the ad; and just last month, a teenager and a 51yo man were arrested in connection with robbing and murdering men who had answered their ad offering ranch jobs.
And those are just off the top of my head.
There have been multiple armed robberies by people who have answered jewelry for sale ads.
So you can pooh-pooh caution, if you wish. Personally, I recommend meeting in public places and not inviting total strangers into the home.
Note also that a buddy of mine had an offer for a gun trade via armslist.com a few months ago. When my buddy said he wanted to meet in a parking lot outside a nearby gun shop, where there would be people around (but they would be gun people), the other guy bailed on the trade. Makes one wonder...