Thanks for your reply, gellchom.
I'm a quiet person and an introvert, but I like to think that I'm not a total conversational wet blanket. Sometimes I have trouble coming up with things to say, but I try my best to keep up my end of the conversation by being interesting and funny when I can, you know?
By conversational narcissists, I mean people who don't seem to have a sense of whether a subject is interesting to others and and no sense of how long they should talk about it. They just go on and on, responding to your questions but never asking ones in return, and when you interject with a comment they just say "yeah" and then continue the monologue.
As for feeling used, I think it's that you've shown interest in them, and they accept it happily, but offer none in return. It's like you offer them a ping-pong paddle, expecting that they'll offer you one in return and you'll play together, but instead they just take the paddle and lob balls at you. Lol!