This happened a veeeeeeeeery looooooooong time ago. I think back in the year 1996.
I was 7 years old at a party. There were many balloons there. I think it was a wedding. Anyway, before I was about to leave with my parents, then I wrote a letter to Nintendo:
I wish you would release Donkey Kong Country 3.
(This was right when Donkey Kong Country 2 for the SNES came out.)
I then tied the rope of a balloon onto the letter, went outside, then let it go. There were other kids there, but they didn't know it was a letter to Nintendo (Maybe Santa Clause, hehe).
Anyway, months later, I recieved a Preview video on Diddy Kong Racing for the N64. Wow! I never sent anything in my life to Nintendo for them to send me that! My parents didn't even know I sent a letter to Nintendo on a balloon.
Weeks later, another Video. It was on Banjo-Kazooie.
Weeks later, Pokémon (Before it even came out in the US).
The last one weeks later, a vid on Jet Force Gemini & Donkey Kong 64.
I guess someone who worked for Nintendo found my letter & decided to send me stuff.
P.S. Someday, I'll get a video capture card & release the vids on the net.