SIC Codes for Businesses

[classicman]

Does anyone work with these? I've been dealing with them for years and it seems that the data gets worse every year.
Did a search today though Sal-es-gen-ie (I don't want to give them any props)
for residential contractors in the state of NJ - the list had a grand total of 18 - FOR THE ENTIRE STATE. So back in to refine the list... Anyway spent over 2 hours messing with all the different SIC codes to realize there is no rhyme nor reason to what code a business gets. Basically ended up as a large waste of time.
The whole point of using this service is to have the business sorted by certain categories. I understand that some may cross into several, but to not really be able to effectively use the SIC codes makes the service pointless.
I tried the online help which led to more frustration, then called the 800#.

The culmination of the "customer service" I received was canceling our contract.

This turned into more of a rant than I intended, but I'm still interested to know if anyone else uses any of these services or SIC codes specifically.