I have helped people many many times. It's a great feeling.
Unless you get those people who look at you like a freak for helping them with a toyline....
I have had many good experiences though. The look of joy on a kids face, combined with the look on a parents face when I saved them money (it's happened, heh)
One time, a parent was on the phone with her husband or somebody and they were back and forth describing the character. I asked her what her kid wanted, and based on the little description, I was able to find it in 2 seconds. After thanking me, she proceeded to talk to her husband about the random guy in the toy isle who was so helpful and saved her day