I remember that the first time I had something about them, it left an impression that was positive - I was startled to realize that there were others in the world who thought of animals as more than just property or objects that happen to move. Whatever the context, it wasn't vegetarianism, though - it was a number of more years before I realized that such a thing as vegetarianism existed outside of a Hindu or other religious context. And it was a couple of years after that before I went vegetarian.
Peta didn't impinge on my consciousness after that first notice until after I was already vegetarian, when they started doing more outre things to garner attention. I understand the point PeTA supporters make about the organization's role in attracting attention to animal causes, but I think much/most of what they do now is counterproductive because it enables the general population to dismiss everyone who is AR as being unrealistic, ignorant idiots. Not all publicity is good publicity, despite the saying.