The idea of cutting yourself due to depression and an immature self-loathing or "need to feel something" is completely different from cutting yourself in a magical performance to produce something. I'm hoping that everyone posting "everyone will think i am emo" has the ability to distinguish the two, and am going to put it on good faith that it's good natured (if not juvenile) ribbing at the effect.
So after you pull the coin out of the arm, you restore the cut?
Is there a reason why your pulling it out of you arm? Why not the foot?
I think this is more of a shock trick than an actual thought out trick.
Spec - "It's in his arm!"
Me - Why is it in the arm?
Not to be mean or anything but it makes no sense. I guess the shock of you cutting your arm open to get the signed coin will be enough for them to not ask any questions.
I guess I'd have to wait to see some live performances to get a whole presentation on it.
I'll use a tired example straight from the annals of two years ago, so forgive me: but you can apply this same logic to a lot of tricks. Not many of them make sense. "You made two cards switch places!" Why? "You bent a coin!" Why? "You made some balls jump around under cups!" For God's sake, why?
You've got to apply suspension of disbelief here: most magic tricks are completely illogical EXCEPT within the course of a performance. Why in the world would a rational individual with time on his hands make some cards change color, or really any of the things we do? Because they perform a magic show for you. Swallowing a coin then cutting it from your arm makes as much sense as anything else magicians do. The audience sees what the magician is doing, and since they're suspending disbelief for this performance, they accept that this is just a gory way to make a coin appear after it went away.
It's geek magic, pure and simple. It fits certain characters. It's squeamish fun for people watching. It's a non-boring way to produce a coin. Take your pick.