I'm an introvert, and I hate meeting new people, but I also think I'm pretty good at interacting. I love playing hostess, and I love good conversation. I'm also pretty easily entertained, so when someone is conversing with me, I'm usually intrigued.
From my perspective, what someone says can tell you a lot about them, so if I find myself at a loss of what to say, my reaction is usually "that's interesting." I think people often think I'm using that as a way to acknowledge that I'm listening, even though I don't care, which is not at all accurate. I say interesting, because things are interesting.
A good friend of mine often asks "Why is that interesting?" but to me, it is so obvious! Just now, she told me her father noticed she had lost weight, and "interesting" was once again my response. Why? Because I didn't notice her weight loss, and I think it's interesting that someone else did.