they likely only need to sign up these businesses in order to ensure they have tap to pay terminals and that they likely will display Apple signage. The real people to sign up are the credit card companies, most terminals these days already do NFC payments but the issue is that the card companies limit these transactions to like $100 because there is no signature or PIN needed. Apple needs to get the card companies to differentiate transactions made by touchID and raise the limit over traditional tap to pay systems