Among the questions (all via text) that he answers?
Well, when a girl asks what she should do about a guy who is interested in her one day, then ignores her the next, Hamm replies, "The world is your oyster. You'll be just fine. Don't define yourself with who wants to get with you. I'm sure you're a lovely person."
On a lighter (and thus, more humorous) note, another gal wants to know if it's gross to break wind in front of one's boyfriend.
"Farting is farting," Hamm points out. "Everybody farts. Go read the book Everybody Poops. Same thing."