The Social Network was a fantastic movie for many reasons: The direction of David Fincher, the music by Trent Reznor, the acting of mostly everyone involved and, of course, the screenplay by Aaron Sorkin. It's trademark Sorkin, with dialogue stacked on top of more dialogue and characters expressing so many different things at once, and that all makes it good. But what makes it great is the screenplay's structure and how Fincher dialled down some of that trademark Sorkin-ness, too.
As Lessons from the Screenplay examines in this breakdown of the film's screenplay, there are impressive scenes in the film that are just pages and pages of dialogue. A lot of that can be compelling on its own because it's coming at you so fast (the memorable opening scene, for example), but it gets taken to another level because the structure (jumping around the timeline from the creation of Facebook to the deposition during the lawsuit) allows the film to show you what happened — while the characters get to tell you how they felt about what happened too.
Fincher also does a great job reeling in Sorkin and editing him, as you can see in the video below, and that prevents the words in the script from falling in love with themselves. (Also it doesn't hurt that Fincher knows exactly when to hold onto a shot, and when to keep cutting.) Sorkin is magnificent at what he does, but his collaboration with Fincher brought out the very best of his work. It basically all adds up to a perfect combination of what was on the page and what ended up on the screen.