I advertise at the location of the timeshare. I never considered anything else.
Craigs list has worked well for me but its always (almost always) last minute shoppers and last minute deals. I did eight June and July 4th rentals plus one for next February, in the last 30 days. I could have done more but I ran out of inventory
Be sure and repost your ad every 2 days.(the maximum permitted). I find that most Craigs list shoppers are not looking beyond the current days posts. Im developing two different ads so that I can have one running every day. Also I like to post late at night (after midnight craigs list time) so that I am the first ad of the day. or the last one from the day before...I get better response that way, rather than when Im lost in the middle of the pack...Also pay attention to your headline, figure out a way to make it stand out