Where does List Source get its data?

Question

Has anyone wondered where List Source (and others) get their data?

I go on all these county assessor sites and they all make me confirm that I am not using an algorithm to mine the data off their records. I'm guessing that as big as LS is, they would probably get caught using some advanced data mining algorithm. I'm sure some small guys can do it and perhaps get away with it.

Can anyone shed some light on this? Where do they get the data from?

Vijay Bhise · Answer

Hi Ed,I can answer part of this as I prepare Tax Delinquent lists for many counties for my clients.You can actually buy data from most counties. Counties usually have mining restricted only to prevent their systems from being jammed due to constant data requests from computers that mine data. They're not trying to protect the data itself, AFAIK since the data is open as public records anyway.  You can request counties to send you property records under the FOIA and they will usually do so for a small fee, but the data is really huge (several hundred MBs) and messy (one large CSV with no formatting). So, it can take an individual days to make this info readable. That being said, larger players like List Source, etc. probably pay the county a fee for accessing their interface and quite possibly are given a different interface to use so they don't disrupt the website / interface meant for the general public. Of course, I'm just guessing here.

Thanks