For Christmas one year, I gave my grandpa a DVD box set of the early "Seinfeld" seasons. My dad thought it was a silly gift because a now-classic show like "Seinfeld" would probably have reruns until the end of time. So far, my dad has been right. Even as streaming has transformed the television landscape, the availability and appeal of "Seinfeld" shows no signs of fading. In fact, it's this ongoing popularity that helped turn director Rob Reiner's production company, Castle Rock Entertainment, into a cash cow.

Named after Stephen King's famous setting on the Maine coast, Castle Rock Entertainment is an American independent film and television production company founded in 1987 by Rob Reiner, Martin Shafer, Andrew Scheinman, Glenn Padnick, and Alan Horn. The company produced numerous acclaimed independent films, including Richard Linklater's "Before" trilogy, several Stephen King adaptations such as "The Green Mile" and "The Shawshank Redemption,...