I am getting dizzy reading all the spins the fans and detractors of the movie are putting on the boxoffice numbers. But the detractor dudes are grasping at the straws here. This movie is a hit, boxoffice and otherwise.
One factor that's important, besides the boxoffice, is how the studio perceives the movie in terms of qualify and popularity. The movie "Superman Returns" is mentioned several times in this thread. I think the studio executives were not exited about that movie and moviegoers reactions were lukewarm (e.g. 6.2 rating on imdb). So despite solid boxoffice numbers they didn't do any direct followup to that movie and eventually did a reboot several years later.
But in case of STID, the studio obviously thought highly of the film. That's evident from early critics screenings, the 9 minute trailer, opening the movie a day early, etc. All indicated that studio was confident they had a good movie (maybe a little overconfident, releasing a day early was a mistake). And the audience and critics reactions to the movie has been very positive, high ratings on cinemascore, imdb, rottentomatoes, etc.
So while the studio maybe a little disappointed by the domestic boxoffice, they are very happy with everything else. So the next movie will be done by the same creative team. They may try a different marketing strategy to get more female and younger viewers, but it will get made and will have a healthy budget (even if it's lower than this one).