Merge/Purge Software

[Joe Norman]

Hello BP community! I have several mailing lists that I have created or purchased for my target area in the greater Baltimore area (approximately 15-20 zip codes). Some lists are small (100 houses or so) and others are very large (3k+). I want to compare the lists to find properties/owners that appear on multiple lists and target them for extra mailing (i.e. do a "Merge/Purge" operation on my list). I've found several companies that offer software to to this (eg. Data Ladder) but none appear to work on Macs/Apples. Anyone else had this problem or can you offer a Mac or web based solution?