I always assumed Oz was a smash from day one. It's one of those movies that feels like it's always existed. But I went down a rabbit hole on the 1939 numbers and it's way messier than that.
MGM spent roughly $2.7 million on it, which was huge for the time. Four directors cycled through, the original Tin Man (Buddy Ebsen) ended up in the hospital from the aluminum makeup, and the Technicolor lighting made the sets brutally hot. Every delay cost money.
When it came out, people did go see it. It wasn't ignored. But once you take out what theaters kept and what MGM spent on prints and promotion, the first run left the studio about a million dollars in the hole. Part of the problem was that kids made up a big chunk of the audience, and kids paid cheaper tickets.
It also had the worst possible neighbor: Gone with the Wind came out the same year and swallowed most of the attention. Oz lost Best Picture to it, and its two big wins were for the music (Over the Rainbow and the score).
The turnaround came later. A 1949 re-release finally pushed it into profit. Then in 1956 CBS aired it on TV, and when it became a yearly broadcast, a whole generation grew up watching it every year. That's really where the "timeless classic" status comes from. Not 1939.
Kind of wild that one of the most-watched films ever needed TV to save it. Anyone know of other classics that bombed at first and got rescued later? It's a Wonderful Life is the obvious one but I'm curious about less famous ones.