It really depends. I don't particularly like them in my soup, but when I'm grabbing lunch between classes I sometimes will. A cup of soup is $3.79, so I'll get crackers cause they're free and I'll be more full. I put the crackers in and eat them right away cause I don't like when they get soggy.
It depends on what kind of soup it is. If it is something creamy, like cream of potato soup, I put ritz crackers in it. If it is something more watery like chicken noodle soup, I don't because then the crackers just turn into a gross mush.