I can personally say that I showed 3 of my friends who weren't originally interested in Smash the EVO stream and now they own their own copy of Melee and Brawl now.
Any person who ventured onto that stream who wasn't completely into Smash probably had the same effect on them. Sure, it's not going to have some mass pull of people going to buy it because the game isn't new and that time has passed but things like that can straggle in a few more customers here and there. As a sale's rep, I can say companies don't say that "Man only 3 people bought that old thing" as bad thing. The company I work for has been around 1949 and we use older products to sell newer products and Nintendo could take the same route if they wanted to and neither is it a new selling technique.
Don't bull**** me either by saying I'm not qualified to speak as a Marketer because, even though I've only been the field for about 2 months, I have already made 45K in career sales and I would have been considered for a managing position if I didn't choose to ship out to the AirForce.