Are your listings posted on Google Base?
Google Base is a free online classifieds system. It has an area for real estate ads. It's growing in popularity even if you've never heard of it before. Not sure why they call it "Base" though.
I spent about an hour tonight studying how to add my listings. It's quite a chore to add them whether you use the easy way or the harder way. The easy way is time consuming, similar to adding your listings into the MLS - for anyone who does that themselves. The bulk method might be easy if you use Microsoft Excel and export the file as a tab delimited text file and upload it using their manual method.
Part of my interest in this is most listings are currently Century 21 and Coldwell Banker. Some listings are from sites like owners.com, visualtour.com, fsbosellbuy.com, etc.. Prudential isn't adding our Prudential listings at this time but intends to very shortly. For this reason I decided to go ahead and add my own listings.
I can add other items to their classifieds system. For instance, my wife has a retail business. I may try adding items, individually or in bulk, to see if we can sell the items on Google base for free. Worth a shot, huh?
Yes I have used google base but like you said it's simply a pain to get everyting uploaded. However that is what my assistant now does :)