Is there still money to be made from “Matlock”?

Within the last few months, television distributors have opened up their libraries of classic content online, making thousands of episodes of programs like “The Twilight Zone” and “The Mary Tyler Moore Show” available free.

On Monday, Warner Brothers is expected to add a new twist, announcing the rebirth of the WB broadcast network as an Internet destination and offering programs like “Everwood” online.

In putting old episodes online, broadcasters are tapping into the “long tail” of niche content that the Internet has monetized. While executives are reticent about the costs involved, and while syndicated and DVD sales remain dominant sources of revenue, the repurposing of long-dead shows is creating another new revenue stream for distributors.

The online re-creation of the WB  a network that disappeared in 2006 when it merged with UPN to become the CW  will represent another step in that direction. While Warner Brothers would not confirm the plans, preferring to wait until a press conference on Monday, Bruce Rosenblum, the president of the company’s television group, said in an interview last week that “premium ad-supported digital destinations that are demographic-specific” are a key part of its strategy going forward.