I was invited by Citi to try this contactless card in the last summer. Citi also offered me a $10 credit for charging a total of $10 in three stores from a list among which CVS, Target, etc. were included. My card works everywhere in the US (and I received the $10 credit by using it at CVS and Target and probably at Walgreens/DuaneRead or Rite Aid) where contactless cards are accepted. I haven't used it in overseas but will try it in London next week.

Note that, Citi added the contactless logo on the back. You need to tap/touch the logo at the contactless pad on the terminal. If it doesn't work, I would call the customer service. Perhaps your contactless payment ability hasn't been activated in the system.