I've spent about 5 months in Ireland this year and have noticed DCC is almost everywhere. I would estimate only 30% of retailers "turn it off". In my experience in Dublin, the merchants always give you the option and let you select for yourself at tourist attractions. At non-tourist attractions, many merchants think you are getting a good deal and, in fact, use DCC all the time in the UK and the US. So I strike up a conversation on how it is a scam. I truly believe the till workers but there have been a few times where I mentioned clearly to pay in EUR and they select USD like nothing happened. Frustrating.