NBC's The Tonight Show with Jay Leno is laying off 20 to 25 staff members in a bid to reduce its budget sharply. According to NBC insiders, the cuts would have been even more drastic had Leno not volunteered to take a "tremendous" pay cut himself to "save as many people's jobs as he could." The Tonight Show has long been one of NBC's flagship programs, and despite a damaging Conan vs. Leno hosting controversy, the show remains a late-night TV staple. Why has Leno fallen under the budget ax? Here, a brief guide:

How deep are the budget cuts?
NBC insiders say The Tonight Show's weekly budget has been slashed from $2.3 million to around $1.7 million. The show employs between 150 and 200 people, so the loss of a couple dozen staffers, while painful, likely won't be debilitating. Reality check: The reduced budget is really a return to a level that was once considered fully adequate. Leno was granted a bigger budget when he briefly moved to primetime, and was allowed to retain it when he returned to late-night. Now he's going to have to make do with his original late-night budget.

Did Leno's pay cut really save jobs?
It appears so. Leno was making as much as $30 million. Now, according to the Los Angeles Times, he'll be taking home $20 million. Those millions of saved dollars potentially rescued the jobs of many of the show's employees.

Is this a sign The Tonight Show is in trouble?
Not necessarily. Leno's ratings were certainly damaged by the bitter 2010 episode in which his show made an ill-fated move to primetime, then abandoned that experiment, and reclaimed its old time slot from Conan O'Brien. But The Tonight Show remains the top-rated show in late night, with 3.7 million viewers.

Why are such deep cuts necessary then?
One reason might be growing cable threats such as Jon Stewart and Stephen Colbert who are splintering late-night audiences. Stewart's Daily Show audience grew by 5 percent last year to 2.1 million viewers, while Colbert added 7 percent to claim an average audience of 1.5 million. "There is no dominant late-night king anymore," researcher Brad Adgate of Horizon Media tells The Wall Street Journal.

Any other theories?
The cuts might simply be part of an overall review of spending at the network. Cable giant Comcast bought NBC in 2011, and has been evaluating its new assets ever since. "I don't think ad sales are off," an NBC executive tells Deadline. "I just think the people who bought this company, Comcast, wants to go through everything at NBC and get their money back."

Sources: Cinema Blend, Deadline, Hollywood Reporter, Los Angeles Times, Wall Street Journal