JFBConnect doesn't support automatically posting new listings to Facebook. We currently only support autoposting new reviews.
Since JReviews uses Joomla's underlying content system and tables, you should be able to use the Content - Article object and have that automatically posted when a new listing is created. I haven't tried that recently, but it did work at one point.
Please test and let us know if that helps get you going.
Thanks,
Alex