In regards to some of the fast food franchises, it is a franchisee decision which cards to carrry. The only Subway I've been at recently that didn't take Amex was on Miami Gardens Drive near 87th ave in North Miami. Almost walked out because of that but I was extremely hungry and I didn't realize until after I ordered that it was not accepted at this spot. Every Jamba Juice I've been too [and I've been to a lot] take Amex.