At the Star Wars: The Force Awakens global press day, despite a major production with video games, Google Cardboard, custom ice cream, photo opps, and more, there was still a veil of secrecy over everything. The location was to be kept secret (to prevent Star Wars fans from showing up, most likely) by press in attendance, and there wasn't footage screened, let alone the film itself.
Both director JJ Abrams and Lucasfilm president Kathleen Kennedy addressed the priority around keeping the film largely a mystery, and basically said that it's for the fans.
"While we were working on the movie, I realized how engaged with the fans and forthcoming Lucasfilm had always been. My nature, which is to keep things quiet, was something that I was certain we were going to have fights about," Abrams said. "But Disney, to my shock, was arguing to not ruin, not reveal, not show every story beat. We've all seen trailers for films that literally show you the movie in Cliff's Notes form, and you go to see the film and go, 'yeah, that was literally the movie. I saw it in a 2 minute, 10 second piece.' So I was very grateful that Disney actually took the lead to keep things quieter."
Kennedy was asked a similar question during the second press conference.
"I think right from the beginning, we've respected the fans. The fans have been the ones focused on everybody getting to be surprised," Kennedy said. "I've had people say to me that they don't want to read anything at all, so they can get to the theater and have it be a surprise. That's what's driving it, and we've tried to respect it."
The air of secrecy will be pulled back soon, though, with the countdown to the film's release now in single digits.