Nice clean graphic.
Consider - someone just handed you this card - you're looking at the front.
What do they DO? What's their business? How do I contact them?
I'm seriously not trying to be a smart alec and it is going to sound trite ... but if I couldn't see the contact info on the front I would assume that it HAD to be on the card somewhere so I'd flip it to see if it had something extra on the back.
As to what he does ... it think when I received the card it would be in some kind of context that would give me the clue as to him being a photographer. I can't see/make out the small text running along the side of the "D" but I'm guessing it might have a photography reference.
I like the simplicity of the card - the front, for me, is intriguing and makes me want to turn it over.
The ONLY thing that would concern ME is handing someone the card and insinuating that they are getting the "D"!!! But if you are confident enough to make a joke out of it (if some-one were to take it the "wrong" way) then its all good. I would be a little uncomfortable with that situation - but that's just me. I only mention it to make you aware of a POSSIBLE reaction from some-one ... so that you are prepared for a response.