@Fafnir: In general it should never come to a point when people are (truly) annoyed by something. But I don't think anybody was.
I surely hope I didn't annoy people too much, practically begging them to buy more Otter Noses. I am aware I do have a problem with noticing stuff like that though. I tried to back away quickly from any face that looked annoyed. If I was not careful enough and still annoyed anyone, I am truly sorry - that was never my intention.
That said, if/when given the chance I'll probably do this all over again. Although as mentioned I'm not sure if anyone was annoyed, I didn't hear a single person complain, quite the opposite in fact. I was rather surprised by people thanking me for "doing such a great job at being a salesman", and even giving me money without wanting anything in return. If anything, I'd say it shows just how willing this fandom is to help a good cause =)
But out of all the people I spoke with, those that seemed the happiest with my sales were those in the Charity team. They were truly passionate about helping their cause, and it showed. I'm positive they'll do great again next year. =)