Courtsey of the MLS, franchises and brokerages.

Be aware, the dark side (zillow) has established that correct information is irrelevant, but extortion does have benefits.

Hint, both Trulia and Z publish agents sales information suggesting it as a rating.

I suspect that most of these sites eventually rank based on the agent who pays them the most.

Easy for a hack agent to cook these figures.

They must have a way just like Z and T did in the beginning. I wouldn't trust the information just as information from other third party property sites can't be trusted. 

Bob Haywood I remember Redfin trying to do something similar. IncredibleAgents.com also give some points for your activities (however, you have to add listings etc in your account.)

I believe on Zillow and Trulia (And now one of the branches of Move.com/Realtor.com - RealSatisfied) get this information from MLS and agents.

Like you, even I wonder how would HomeLight.com get this information?

Good question.  Title companies?  Boards?

No idea who they are. Another site wanting our money

Their commercials are cringeworthy. There's no way they can reliably rank Realtors. Too many variables and hyperlocal nuances.

I have not heard of this and can only think that they are trying to sell leads.

Bob - I recently heard of Homelight.com, and am also checking them out just to see what they are offering. I'm not sure how they obtain our sales info.

It looks like they charge agents a 25% referral fee.

Sounds like another scam that will charge agents for ranking