Originally Posted by Sunny Day

For years, "real movie stars" might be on TV for something special. But none would make a commercial. It was a huge event when John Wayne made an aspirin commercial. That was like the dam breaking and "real movie stars" went to the small screen for shows or commercials.
A lot of movie stars found great TV success even before The Duke's commercial.
Red Skelton, Jack Benny, Bob Cummings, Buddy Ebson, Andy Griffith and James Gardner to mention a few.
It was the same when movies first came out, actors shifted back and forth from Vaudeville to the movies. Several like the Marx Brothers did Vaudeville, movies, radio & TV.