The gravy train had to slow down at some point. After three record-setting weekends, plus over thirty other records set at the box office so far, the galaxy far, far away came back down to Earth a bit on their third Monday in domestic theaters, their first non-holiday week.
Star Wars: The Force Awakens took in an estimated $8 million at the domestic box office Monday January 4, 2016, a substantial drop from last Monday's $31.4 million and Sunday's $21.5 million. That's not actually bad news, though; your average successful movie gets around a $4-5 million first Monday in non-Holiday weeks. That, on its third Monday, and first non-Holiday it could double that average shows The Force Awakens strength.
The slight slowdown, though, puts the movie at $750.2 million domestic total, $10.3 million below Avatar's current domestic record. That means Force will more than likely take the domestic title on Wednesday, not on Tuesday as previous estimates predicted.
In short, while on the surface the drastic drop seems significant, when you look at the circumstances, it really isn't. It's actually major that it's still getting $8 million on a Monday after three weekends.