This is a question we don't know the answer for. However, it is a question we can help YOU figure out the answer to.
There are over 100 lead providers out there from Zillow to Homes.com. You can purchase leads from any of them. The only way to know which one is best is to try the ones you believe in and track the results you get (or don't get).
Lead Manager is an easy way to manage and track multiple lead sources like this at one time. You can measure # of leads, conversion rate, and more by using Lead Manager. Whatever path you take, you need some type of system to ensure quick follow-up with the leads so you can get accurate numbers on how well they convert and ultimately how many dollars the leads turn into for you.