I would like to point out something from craig's view. It seems they have the world carved up into 4 geo levels.

1. Local

2. Regional

3. National

4. International

It is easiest to post local. For example my IP tells craig that my local area is San Francisco Bay Area. Including Oakland down to San Jose. This is a huge population area that I can post in with little effort.

Now my regional area seems to be north of Bakersfield all the way to Redding and as wide as Reno. But does not include the LA Basin, San Diego or Vegas. Basically what is considered Northern California. This is a little harder to maintain ads in but if you are careful not to get flagged to much craig will let you get away with it.

National is obvious... the continental USA for me, as far as I can tell. I have been able to successfully post nationally but only in limited categories. Easiest under "all for sale / wanted". Hey that works for me.

I have had some experience with International posting but it is limited. Have posted in Canada, UK and Australia and made sales in all but Australia. Not any harder than National except there seems to be a higher risk of flagging because in some areas you may have only one ad of half a dozen for the whole day. I stick with the larger cities and avoid posting in the tundra! lol. Have had some flagging due to my English ads placed in French craigs in eastern Canada.

This is still a learning process for me and some promotions seem to be better accepted by the average craig surfer than others. I have had best results with physical products. Digital products seem to be persecuted a bit more readily. Most likely by the brick and mortar posters in local areas. "Make Money" products and services (like WAU) are really looked down on. I get both ghosting and flagging immediately so it is both craig bots and the public. It can be done but by the time you water down the message it is tough to get anyone interested. That being said I still get 1 or 2 visitors a day to WAU with only 4-6 regional ads. Building gradually so ads stick.

I am not offering any actual services like plumbing or fixing HVACs etc so I haven't tried the service categories. Have heard you are limited to only 3 local postings per account and there are, in some cases, huge flagging wars between the locals. My motto is "No Boss And No Clients" so being a "Stealth Affiliate Marketer" is more my style... the general categories work best for me.

I have neglected to mention another free tool I use is Google Maps and it is invaluable since I didn't do well in geography at school. Craig has a corny way of naming areas and sometimes it is difficult to figure out what their list is called in a certain area. Like "Tri-Cities" means Kennewick WA and surrounding towns or "Gold Country" means eastern California around Placerville. A simple "craigslist for gold country" or "craigslist for Placerville" Google search and then look at the housing category will give you the surrounding cities people are posting for.