I've been posting quite a few free classified sites lately in an attempt to raise my main site's profile.

There do seem to be some sites that really stand out, for instance Craigslist and US Free Ads (which has an Australian version -- as so many others do now), also Wikalo.  But I've been posting at many others as well.

I've been searching for some of the keywords that I've put in my ad and have been pleased to see that some of my ads show up -- even ones that I posted only a couple of days ago. 

If these ads are indexed, then surely the URL that I've put in the ad must be also.  So, I'm assuming that my search engine rankings will go up a bit as a result.