I took it down.. all in all I gave away around 8000 gralat out of my own pocket.. it's true, many people seemed to just want money and not give to others.. and the sign even says you can donate.. I figured that would hint that it wasn't some unlimited supply of money.
I wasn't very pleased with the fact people actually COMPLAINED about it.. "WTS I GOT RIPPED OFF IT DIDNT GIVE ME 100" "This thing is stupid I didn't get as much as him!" "How can I get more?" not to mention that once people got their gift, they touched all over the npc at every angle hoping to get more out of it somehow.
It was fun and I'm happy to give out some of my excess money, but I don't think I will be doing anything like this again until the economy isn't so tight to the point where people will kill their own friend in order to get some money.
and a nice screenshot of how thankful most people were to get a nice break with some free money: