Been on both ends of trade shows.
This sounds like a dud to me.
As far as video for trade shows, that is often done well ahead of the show. These are often looping dvd's that run in the booths during breaks, or in the BG. There are usually a supply of the DVD's to give out to serious customers, and version for the company web site. These are mostly VO and B Roll of the product and service. Don't recall ever seeing one that was a recording of the booth pitch from last years show. Not sure what the value of that would be.
IMHO, for anyone that missed the show, the standard VO/B Roll piece with decent production values would be a lot better to view, then the booth pitch at the show. Of course you could dress it up with a lot of cut-aways and such, but what you end up with is still a lower quality version of the standard VO/B roll piece.
As far as going around the show trying to pitch your business, good luck. Best way to sell at a trade show is to be an exhibitor, not an attendee. At some shows, indiscreet selling by attendees can get you booted from the show, since selling booth space is how the show makes its real money. This isn't your case, but there is also the possibility of complaints by exhibitors caused by your activities, which may limit what you want to do.
The reason most exhibitors are there for is to sell their product/service, and often won't be interested in anything that distracts from that. You might be able to give out some cards, but other than that, I don't know. A lot of time, the staff at these booths are there because of their knowledge of the product/service and not the people that hire video production anyway.
Scott Sheriff
Director
SST Digital Media
http://www.sstdigitalmedia.com