Listings aren't hard when they are free, only way this business ever has true success is if they can get agents paying to list and reach the audience they have built.
Even with Rent.com.au, I struggle to find any agents that are willing to pay the $10 per listing. A few are using the Smart Plan, which i assumes costs them a bit more to cover the $100 gift voucher, but not seeing a lot of traction on this front.