Erin,

I have registered on several free sites because they were free.  I have never had any potential customer tell me they found us on any site other than Source of Title.  This seems to be the site where those looking for abstractors come to find abstractors.

[If my local competitors will kindly skip to the next paragraph] I have also found that the paid listing is well worth the nominal fee.  Any party can view your contact information if you have a paid listing here.  To view information about a free lister, the person looking for you must have a subscription.  I believe that's how it works anyway. 

I am not a shill for SOT, just a big fan - and a willing cheerleader.  I would not discourage you from listing on free sites, though.  I am sure they are worth every penny you spend to advertise there.