The Business Lists at PostcardBuilder are supplied by Compass Marketing Solutions – www.cmsdm.com. Compass is a leading compiler of business data with over 16.6 million highly responsive and deliverable businesses by SIC Code and other firmagraphic selection options. Their database is compiled from multiple data sources including telephone directories, government filings, and annual reports and is phone-verified and updated monthly. Mail delivery is typically 94% and phone accuracy 90%. For more information about how the list business works, go to Overview of the List Business.