In making the leap to television, they demonstrated that two rather unremarkable-looking newspaper hacks could make for good content, in part because they spoke their minds and crossed swords frequently. And their binary aesthetic — thumbs up, thumbs down — not only snatched back criticism from the rarefied confines of elite critics, it democratized the practice, neatly predicting an era of Facebook “likes” right down to the use of the thumb. (No dummies when it came to the business end, they trademarked the phrase “two thumbs up,” declaring legal dominion over the concept they helped popularize.)

In 1982 they left public television and cut a deal with The Tribune Company, which was getting into the TV syndication business, that not only paid them well but cut them in on 25 percent of the profits. Mr. Ebert once jotted down some of that math on a napkin to show a local television personality in Chicago how syndication could make her very well known, and perhaps, wealthy. Oprah Winfrey took that advice to the bank.

Together, Siskel and Ebert became the most famous and well compensated film writers in history by using television to spread the word. Carson, Letterman, they were all happy to have Mr. Ebert and Mr. Siskel stop by to brandish their thumbs on the late-night couch.

They continued to roll, signing on with Disney in 1986 and changing the name of their show — which had been “Sneak Previews” and then “At the Movies” — to “Siskel and Ebert and the Movies.” A year later it was shortened again to just “Siskel and Ebert,” because everyone know what their names meant by then.

Mr. Siskel was the more business-minded of the pair, and Mr. Ebert wisely allowed his frenemy and their agent to cut the deals for their show. But Mr. Ebert was hardly a dummy when it came to business, and in some respects he was a visionary.

He used technology to reiterate and reinvent time and again. When illness wiped out his voice, he took to the Web, developing a manic and persistent presence on RogerEbert.com, and when it became clear that no surgical remedy could restore his voice, he used a synthesizer to continue his life as an impresario and showman. At a time when media companies are scratching their heads about how to successfully stage special events, he was 15 years deep into Ebertfest, his personally curated movie festival in Champaign, Ill.