I've heard of at least one person going vegetarian after hanging around with someone who never (or rarely) mentioned being vegetarian, and I've also heard of people being ticked when approached and then changing later.
Humans are smart and yet stupid. I wonder how many people would change if the animals were slaughtered in the streets--with blood running everywhere! (I imagine this occurs in some countries.) That doesn't seem quite as tasty now, does it?
Betty