I sent a campaign targeted at 2 client categories- people who'd had one of two different service categories (Body waxing or Facial Waxing) There was no option for "or", only "and" which wasn't the list that I wanted. Therefore I had to send the campaign twice, once to each categories, and to ensure I didn't annoy people by sending it to them twice if they HAD had both service categories, I had to manually go through and remove the addresses of the 274 duplicates when sending the second campaign.