Just letting others know my experience. I have my LTR SFH listed on the Zillow network, for $29.99, and also paid the $99 to list through Redfin, which is Rent.com. I've had at least 30 inquiries/messages from Zillow in the few weeks I've had listed, compared to 5 total views on Rent.com and 1 inquiry. I will save my ad money in the future and not list on Rent.com, at least for this asset type in this market.
Thanks @Mohammed Rahman, I am on FB as well, and probably listed on there later than I should have. I have gotten some good leads from FB, but its also frustrating to continually respond to "Is this still available" and then get no further response.