If the movie Man Of Steel had Ads in our world then?

In the new movie Man of Steel you see real life ads, such Nikon, IHOP, Sears and 7-Eleven. According to producer Deborah Snyder (wife of director Zack), the product placements were intentional because they wanted this Superman to exist in our world.

Then wouldn't Superman already have been known since the comic books were published in June 1939?

Yes he would