My Pet Peeve

I like to send people e-mails. When I see a story or a video that I think someone might be interested in, maybe it's about their college, their favorite actor or their hometown, I e-mail that person. All too often the response is "I saw that."
I know I am not the only person who is plugged in and following stories on the internet, and I don't mean to come off that way, but don't you have something more interesting to say than "I saw that?".
Why do you feel the need to let me know that I am not the first person who told you something. And so what? Sorry, you've heard it before, but can't you pretend you didn't and have a conversation with me about it?