Stephen Colbert doesn’t have to worry about being replaced by The Mentalist. Funny is money, CBS chief Les Moonves reminded investors in his comments about The Late Show With Stephen Colbert today in a Q&A session at the Bank of America Merrill Lynch Media, Communications & Entertainment Conference.

stephen colbertThe evening daypart already is “very profitable,” he says. But the show’s previous host, David Letterman, couldn’t take full advantage of the opportunity. The average age of his audience was 60, while Colbert’s average when he was on Comedy Central was 37 — a more desirable target in the eyes of most advertisers. “It’s a younger demographic and a hipper demographic. So Colbert could be a significant profit center.”

Indeed, last night “Colbert booked a ton of money,” Moonves says. “We didn’t expect it to be that high.”

And since CBS now owns the show — which it didn’t with Letterman — there’s an opportunity to profit from ads on clips distributed online.

“Dave wasn’t into it,” the CBS chief says. “It’s a growing area.” Indeed, on NBC Tonight Show host Jimmy Fallon’s online numbers “are phenomenal. We think Colbert’s numbers will be phenomenal as well. … It’s a great secondary source of revenue.”

The discussion of late-night buttressed Moonves’ upbeat case for his company. Investors are skeptical: Like most media companies, CBS’ stock price fell more than 17% during the past month after Disney acknowledged that it lost subscribers at ESPN, leading it to lower a financial forecast for pay TV channels.

“We’re not part of that,” Moonves says. “We’re not selling 30 channels that people don’t want to pay for.” With shows including Colbert’s and NFL games, “everybody has to have CBS.”

Although “it hasn’t been a great year” in advertising, Moonves said he’s encouraged by initiatives to sell ads based on seven days of viewing — up from three and one — to take advantage of viewers who time-shift. Along those lines, he wishes that people would stop focusing on overnight ratings. “Elementary, although it looks like a moderate success, for CBS it is a major profit maker,” he says. “Business people and journalists don’t understand what’s happening.”

Meanwhile, CBS is covering all bases by expanding into digital. Moonves says he’s “extremely pleased” with the CBS Logo 2initial public response to Showtime’s online subscription offering. “We’re still figuring our way. The numbers have been terrific.” The company is “exploring” the possibility of introducing it outside of the U.S.

Moonves also is “guardedly optimistic” that another subscription service, CBS All Access, will win the right to include NFL games. The league “is doing more and more online, they’re experimenting more” including a recent deal to show a game on Yahoo. If CBS could offer NFL online then that “would be a game-changer.” Along with CBS airing Sunday NFL games, it is partners with NFL Network on the Thursday Night Football franchise.

The CBS chief doesn’t believe that content companies will look for mergers to respond to AT&T’s acquisition of DirecTV or Charter’s plan to buy Time Warner Cable. CBS has been seen as a potential merger partner for companies including Lionsgate, AMC Networks and Time Warner. Yet Moonves says he doesn’t “look for major acquisitions out there.”