As you know ML is not the lowest cost provider of leads.
As with any lead generation system, it's success is entirely dependant on your ability to convert.
Here is some really, really good news.
90% of an idetnifiable subsite of ML leads DID sell their home within 12 months. Moral to the story: there is real fish in the pond. You will need to know how to fish.
Best of success to you,
Annette Lawrence, Broker/Assoicate
Remax Realtec Group
Palm Harbor, FL
This is a great question, but you might have more luck in getting answers if you narrowed your post down to a specific area, instead of "All Locations".
I'd recommend "Houston, TX" as it's the most active community closest to you, and you can find it here: http://www.trulia.com/voices/activity/Houston-Agent2Agent-42-18875