I actually got my two best gigs ever from Craigslist. One was my very first writing gig ever--I didn't even know I wanted to be a writer. An acting job in Alaska fell through at the last minute, and I had already quit my job at Universal Studios...so I needed cash fast. Saw a Craigslist ad for someone to write about Walt Disney World--sent a query, met the guy at Red Lobster for dinner, walked out with a signed contract. $50 a post, 5-6 posts per week, full creative control, and he bought me an annual pass to Disney. I kept that gig for about two years.
My current best client came from Craigslist about a year ago. I don't want to reveal my rate, since I'm still actively working for him, but it did start out on the low side (but not shockingly low). It was a startup travel site that I really believed in, and my other gigs were keeping me going, so I took a chance. Got a 33% raise within the first three months, and just got an additional 20% last week. He's also provided free business cards and frequent bonuses. I have full creative control over my content, and he's extremely supportive and encouraging. In addition, he's always willing to provide a letter of assignment--the sheer amount of free travel I've gotten from this gig is truly impressive!
I know there's a lot of crap to weed through on Craigslist, but I've found that the gems are worth the hassle. Just my experience.