Box office numbers are interesting to track over their respective runs. But for the studios/distributors, they profit far more off a movie that makes its money upfront. Because they get a much larger share of the profits for the first couple weeks.
"The studios (for these bigger films, we'll now assume the studios are the distributors) take a higher percentage of the box office gross in the first and second week. It fluctuates, but we'll generalize and say that they take 80% of the box office take with theaters taking just 20%. Once the third week roles around, the studios take less. In this case we'll say 60%. Theaters take 40%. With each week after that the theater take raises while the studio take decreases, until a certain agreed point." - Ken Miyamoto, Produced screenwriter, former Sony Pictures script reader/story analyst
So for Star Wars: TFA, the studios/distrib could have made $521.5 million off of its $652 million gross through its first two weeks. For its third week, the studios could have made about $71 million from its $118.4 million earnings. The studio/distrib have already earned $591.5 million under these conditions.
Now let's compare that with a slow burn movie such as Avatar. Avatar made $283.6 million in its first two weeks. The studio/distrib could have earned around $226.9 million from that. And if we take the rest of its earnings and give it the 60/40 split for all of it (which is giving it a more than fair shake according to the info above), the studio/distrib would earn $286.1 million off of the remaining $476.9 million.
So, in total, the studio/distrib for Avatar could have earned $513 million from it's entire run ($760 mill).
Given the same factors, Star Wars could have earned Disney/distribs $591.5 million off of its first $770 million made in theaters. And it will make the studio/distrib even more (albeit at a much lower percentage of return) off of the remainder of its run. Let's say it hits $920 million. If we say the studio and theaters split this remainder 50/50, then that would be an additional $75 million to the studio/distrib.
So while for some of us, these continuing numbers are interesting, for the studio/distrib they are much happier when their movies open huge and bring in alot of money in their first few weeks, because more of that money goes to them.
P.S. Based on a number of other articles I read, the split gets much worse than the 60/40 I allotted to Avatar. In some cases by the 5th weekend a movie will be 25/75, with the 75 going to the theaters and it will remain that way or go even lower to 20/80.
TL;DR Studios make more money off of movies that open big vs movies that earn their grosses slowly.