OK, I delved into a bit of this over on the Craigslist poll, but here's some more in-depth info on Craigslist.
Note: I have been using ONLY craigslist and window signs as advertising since June of 2005, as my company refuses to authorize a marketing budget of any kind.
Also: I have rented about 150 apartments a year this way, alone. I have no assistants, I have no photographers, I have no writers. I do the ads, the leases, the showings, the background checks and the floorplan drafting.
However: I am in a major metropolitan area. My dad tried it in a more suburban area and it didn't work.
However however: I am a coder with 10 years of experience, so I can write my own code. There is no better investment of time if you're going to be advertising on craigslist. You don't need to go beyond flat HTML.
Here's what I do. First of all, I watch craigslist postings. If I see a trend, I leap on it, but in my own way. For example, people started using Google maps in their ads. I started using walkscore.com and everyblock.com instead. Now I'm starting to see walkscores pop up in many other local ads, so I'm planning my next big move.
Secondly, I diversify my templates as much as I can. I have about 15 templates in use at once. They're all drastically different styles. Some are grungy and take a super-honest type of text. Others are professional and glossy with high design values. I take my cues from websites that are popular with my target clients. The hipster types get designs based on twitter or threadless.com. The home decor types get a design based on etsy. Pack rats get ads done with lots and lots of whitespace so they can make notes on the printout.
Third, I pack in the info, but only if the target market responds well to it. Lower income communities don't need floorplans, don't have any idea of square footage, don't care how the grounds look, but links to youtube walkthroughs are very helpful. The younger kids don't care if there's a washer/dryer - they can do laundry at their folks place - but they do need to know that there's upgraded wiring and a wall big enough for their TV.
Fourth, I devote a lot of time to it throughout the day. I post 5 ads every 2-3 hours, six days a week. I take replies through phone, email, youtube, and now twitter.
Fifth, and this is crucial, I automate everything I can. Every template has a form on my private server where I can just pick my photos, type in my gloss text and it spits out the final code. Just like postlets, but I control the look and the feel. It requires about a 2 day investment of time twice a year to design and change out a few templates. The rest of the time it's just point and click. Once I've written an ad, I save the code to a database so that when a similar floorplan comes up I can reuse it.
Like any form of advertising, you get out of craigslist what you put into it. With the classifieds, you paid money - that was your investment. More money = bigger ad = more eyeballs. With craigslist, there's no cost (except for a few places), but the time investment required replaces the old monetary investment.
