I would say I have had maybe a dozen or so serious enquiries from free sites in teh last year.
But I have seen them climb up in the results as a result of our listings.
If you rank below them, and they rank above competition, then maybe ad listings is a good idea.
_________________________
[url="http://www.foreclosedjapan.com"]Japan real estate[/url] | [url="http://www.foreclosedjapan.com/openrealty/search.html"]Japan homes for sale[/url] | [url="http://www.foreclosedjapan.com/openrealty/search.japan.condos.html"]Tokyo apartments listings[/url]