Most entertainment merchandise skews to youth: Think lightsabers from "Star Wars." Wands from "Frozen." T-shirts from "Glee."

But five hit TV series — "Empire," "Downton Abbey," "The Good Wife," "The Biggest Loser" and "Star Trek" — reveal how creative and diverse products can be, and that adults are just as keen as kids to own a piece of a show they adore.

In fact, each program has its own distinct niche.

"Understanding how fans feel is more of an art than a science," said Liz Kalodner, executive vice president and general manager of CBS consumer products. "You can have fantastic ratings, or simply a show with dedicated, passionate fans and a great merchandising hook."

Big picture, licensed entertainment-related products generated $11.9 billion in U.S. retail sales last year, up 8 percent from 2014, according to trade publication the Licensing Letter.

The runway has fueled the runaway success of Fox's "Empire" since its debut a year ago January. The characters are clad in Prada, Burberry and Gucci.

Hood by Air has a line inspired by the show, and Saks Fifth Avenue launched its own clothing and accessories line before the premiere of the second season. Participating retail high rollers include Alexis Bittar Jewelry, MCM Handbags, Jimmy Choo Footwear and Cushnie Et Ochs Womenswear.

Carole Postal, president of Knockout Licensing, enchanted by Downton's writing, characters and Edwardian setting, pursued the British show six years ago–before PBS aired it stateside. "The $3.67 billion U.S. quilt market alone turned out to be a bonanza," Postal said.

The popularity continues past the end of the show, just like "Star Trek."

Trekkers' geek minutiae drives a galaxy of spin offs: Borg Cube mini-fridge, captain's chair pool float, "communicator" Bluetooth phone, Starfleet Academy diplomas, Spock hand-signal business cardholders, and even a sushi set with chopsticks forming Enterprise's twin engines.

"This is what we do all day — come up with these," CBS' Kalodner said.

Hundreds of new collectibles join the starscape yearly, driven by devotees via social media. "We have a real-time connection and what once was business-to-business has become a direct-to-consumer business."

"We're lucky to work on a brand with that kind of dedicated fans," Kalodner said. "They have the true love of a sports team follower."