Regarding the actual movie....
We cannot assume that because Insurgent did so well on opening weekend or even a bit thereafter that it would do well enough to guarantee the Allegiant and possibly Four spin off movies.
While production on the 2 Part Allegiant movie has been confirmed, with a start date of May 16 2015 to commence filming, along with the actors and crew returning, it still has not been officially greenlite. After all, a similar predicament happened with The Mortal Instruments: City of Bones, which was due to start production on its sequel only a month after the first film came out. They even announced that they would still be continuing to make the second one even after the first movie failed to grab interest, only to now have it be cancelled & rebooted as a TV show. Even though that is a reboot, they are apparently coming up with ideas that could make it even more different from the books than the movie. Same with The Amazing Spider-Man 2, which is now rebooting its franchise yet again even after an impressive opening weekend and a fairly decent overall gross.
Like I initially posted, we need to spread the word about The Divergent Series: Insurgent and make sure it does well enough to not have its franchise be discontinued, for there is no guarantee of a reboot, and even if there is, despite the changes, there is not really much else they can do that would be different enough to make a reboot without changing things even more than what they have already done. We cannot harass and “make” others go see it, but we can “help” them go to see it. We just need to be casual and not seem so desperate. We need to show and help people see why we love this series and in particular this movie so much, which could also prove why they could also love this series and movie as much too.
Even if you did not like Insurgent, or even the Divergent movie for that matter, please give it a/another chance. After watching Insurgent for a first time, I actually want to go back and rewatch it again and again, and already have plans with different groups of people to go and see it at least 2 or more times in theatres. Rewatching movies has its value in seeing things you maybe missed the first time, as during that first time, you are absorbing and figuring out information being presented to you, such as what is going on, even if you may already have an idea of what is going on. Then the second time, you can pick up on some of the humor, lines or other details that you missed the first time. As this movie is in 3D, a good idea is to see it once in 3D, then again in 2D, and perhaps a third time in IMAX, as it is being offered in that if you have access to it. DO NOT watch it online, for that will only ruin it for others that do want a sequel to it, and besides, you are actually more likely to dislike it if you watch it online per the bad quality not engaging you into the full experience. I have also discovered through others and myself personally that if you rewatch a movie that you disliked the first time, you more often grow to like it, or at least not dislike it as much. Some other movies like Cinderella and Furious 7 are already either doing really well, or are almost defiantly going to do well, so you perhaps do not need to see them right away.
Besides, there is apparently an after credits scene (PLEASE NO SPOILERS) of Insurgent, so therefore you have another reason to go and see it. Just watching it or the movie online or even reading about it is like cheating and again, you cannot really feel the experience or emotion without the best quality of it.
Please consider what I have said. We have the power to influence the movie’s success no matter how small. After all, we are the people that made Insurgent’s movie, let alone The Divergent Series itself possible and with that so beloved and successful.