I recently purchased 6 rare Nintendo promo VHS tapes from the 1990's. To my knowledge most of the videos have not been seen publicly since they were made. They are now on youtube for all to enjoy.
The videos are a fun trip down memory lane and make it pretty obvious that there have been big changes in promotional video style in the last 20 years.
Nintendo World Championships 1990 Recap
http://youtu.be/A2OpRgo0dQI
Campus Challenge 92 Sales Presentation
http://youtu.be/kjpl82GazPE
Nintendo PowerFest 91 Sales Presentation
http://youtu.be/_8QEz3cCA8A
Ken Griffey Jr Baseball Promo Tape
http://youtu.be/PNfxp0CfESs
Nintendo SCES 1994 Marketing Video (Summer Consumer Electronics Show)
http://youtu.be/nNA3R5g55X0
"How We Do It" - Marketing video for prospective retailers and business partners
http://youtu.be/GMEskzqVoyw