Where the Wild Things Are, the children’s book turned movie, was number one at the box office last weekend, and its Facebook page has been one of the fastest-growing on the site in recent weeks. The page had reached 1.74 million fans by the time we wrote about it on Monday as part of our weekly look at the top pages on Facebook.

This week has also been good, although not as good. Now we wonder what’s next.

The page reached 1.82 million fans as of Thursday night (Friday’s numbers aren’t in yet, obviously, as it’s still Friday). So that’s already another 80,000 fans in four days. But, judging from PageData, growth is tapering off.

The question, now that the movie is out, is what how the page can be put to use. The movie is based on a book published in 1963, that has over the decades become a standard part of children’s literature. Any previous pages for the book were apparently folded into the movie page. The only other pages for either the book or the movie on Facebook today appear to be unofficial, and very small.

This means that any future efforts to promote the book will either have to go through the movie’s page, or start over at zero with a new page. Maybe that’s okay, as author Maurice Sendak helped work on the movie — and presumably has a personal and financial interest in its ongoing success.

But after a big pre-release publicity effort, including a funny profile-picture creator application, and the surge of the opening weekend, the page has been underutilized. It has only been updated three times since last week, and only with links to a couple articles about the movie and a trailer clip.

This lack of engagement on the part of whoever is running the page is certainly not helping to further promote the page, the movie, or the book. Which is too bad, because once pages start to get popular, they tend to get more popular — when one friend engages with the page, their other friends see this activity in their news feeds and on the right-hand highlights section on the Facebook homepage.

The page has had a good run. But whoever is controlling it — whether the movie’s producer, Warner Bros., Sendak, his publisher, or whoever else — now needs to keep things moving. Regular status updates,, like mentions of how fans have received the movie, could keep people engaging with the page.

Right now could be an especially vital time to keep interest going, as the movie already appears to have the makings of a cult classic. For example, Lots of late teens and 20-somethings showed up to theaters last weekend in full movie-themed costumes. The Facebook page could be a way to stoke those feelings now, and keep them going for a long time. This might boost movie and book sales going into this second box office weekend and well beyond.