"The Big Store" is American con artists' jargon for a facility used by con artists in a 'Big Con', that is, one that requires multiple days to pull off, with a realistic setting, characters, etc, essentially a full-on drama put on for the benefit of the mark. The Big Store itself exists to be dressed up as, e.g., a brokerage or gambling house, depending on the con. A well-managed Big Store can go from an empty set of rooms to a bustling office with activity in all directions--and back again--in a matter of a few hours. Not seen very much these days, the Big Store had its golden age en the 30s and 40s, around about the time this movie was made. A well-known film example of a "Big Store" con is the one played on Robert Shaw by Robert Redford and Paul Newman in The Sting.
The Marx Brothers announced that this would be their last film, but they actually went on to make two more.
Lee Phelps is credited in studio records/casting call lists for the role of "Piano Mover" in this movie, but the two piano movers in the film were Adrian Morris and Ethan Laidlaw.
Groucho Marx was bitter when he was called for retakes on the "Sing While You Sell" number on a day his son Arthur was playing a tennis match. He was even more upset when he got the lines he was to speak in the retakes and found them "six times as unfunny" as the ones they were replacing.
Although William Tannen is credited as "Fred Sutton" in the movie's credits, he is called "Chris" by others in the movie.
British Prime Minister Winston Churchill was watching a private screening of "The Big Store" when he received news that Nazi second-in-command Rudolf Hess had flown to Britain on an unauthorized mission to end the conflict between Britain and Germany during World War II. Churchill decided that the news was so unimportant he ignored it, went back into his screening room and watched the rest of the movie. (in "An evening with groucho" (1972) groucho tells this anecdote but the movie he refers to is "Monkey Business").
Final film of former silent screen star Enid Bennett, who has an unbilled bit part as a store clerk.
There are a number of links with the 1932-1933 radio series "Flywheel, Shyster and Flywheel", which starred Groucho Marx and Chico Marx (for obvious reasons, Harpo Marx didn't participate in the radio show). In the series Groucho played Waldorf T. Flywheel, a lawyer; in this film he plays Wolf J. Flywheel, a private detective. On radio, Chico played Emmanuel Ravelli, Flywheel's assistant; in the film, he is simply known as Ravelli, and teams up with Flywheel midway through the story to help solve the case. Nat Perrin, who receives story credit for the film, was also the co-writer of the radio series. One episode of the radio series took place in a large department store, although beyond this basic premise there is little similarity between the two narratives.
This is the only film of The Marx Brothers where Harpo Marx is initially teamed with Groucho Marx instead of Chico Marx.
Tony Martin's "Tenement Symphony" was later razzed by Groucho Marx as "the most godawful thing I'd ever heard."