Conversation so far:
How much money has he made?
He could have earned up to $30 million each year depending on ratings for Leno, compared to a $20 million annual salary during his last years at Tonight.
How long was did he work for NBC?
Leno had a contract for five years  for the show.
What other financial impact did the show have?
Each airing of Leno cost about $350,000 to $400,000 versus up to $3 million for an hour-long drama.

Question: How did NBC benefit from this?
Self-contained rewrite: How did NBC benefit from The Jay Leno Show?