It is a 1927 film directed by Clarence Badger, starring Clara Bow. Bow plays Betty Lou Spence, a shopgirl at Waltham's, "the world's largest store", in New York City. Like many of the shopgirls at Waltham's, she's attracted to the handsome young heir to the business, Cyrus Waltham Jr. Betty gets a break when Cyrus's dimwitted friend Monty notices her and asks her out. Betty isn't interested in Monty but she uses him to get introduced to Cyrus, and soon Cyrus and Betty are in love. In the meantime, Betty is providing a place to stay for her sickly friend Molly and Molly's out-of-wedlock baby. Monty gets the mistaken impression that the baby is Betty's, leading Cyrus and Betty to break up. When Betty finds out that Cyrus broke up with her because he thought she was an unwed mother, she decides to make him fall in love with her again in order to break his heart.It was loosely inspired by an article by romance novelist Elinor Glyn, who rather vaguely defined the concept of "it" as self-confidence and magnetism that attracts other people. The movie was a big hit for Paramount and made Clara Bow a big star, who was actually called the "It Girl". It was selected for the National Film Registry.
- Amusement Park: Cyrus takes Betty to one, probably Coney Island, and they ride the rides.
- And Starring: Despite only having a brief cameo, Glyn gets an elaborate "And Madame Elinor Glyn" credit at the bottom of the cast list.
- Based on an Advice Book: The idea of "it" as a slang term for sex appeal, charisma, magnetism, etc, was popularized by Glyn in a 1927 feature in Cosmopolitan, in which she wrote about how people can supposedly attract others to them.
- The Cameo: Elinor Glyn, who popularized the idea of "it", makes an appearance.
- Department of Child Disservices / Moral Guardians: A couple of old biddies get the idea to take away Molly's baby, supposedly because Molly is in poor health and jobless but probably because she's an unwed mother. Betty then insists that she's the mother in order to get the old biddies to get lost. Unfortunately, Monty is there, and relays to Cyrus the news that Betty has a kid.
- Longing Look: Bow gave a famous "triple take" when Betty sees Cyrus for the first time—lovesick longing, transitioning to a lustful gaze, transitioning again to innocent wholesomeness.
- Marilyn Maneuver: Some three decades before the Trope Namer, Bow has her skirt blown up by a gust of air at the amusement park.
- Poor Communication Kills: Betty claims that the baby is hers to fend off the Moral Guardians. She has to tell Monty that the baby is hers because the Guardians are lingering on the stairs. Monty blabs to Cyrus that Betty has a baby. Cyrus, who still wants Betty, then makes an offer for her to be his mistress, without bothering to mention the alleged baby he just found out about. Betty, who has no idea what's going on, indignantly breaks up with Cyrus and quits her job at Waltham's.
- Rip Tailoring: After cajoling Monty into inviting her out to the Ritz, Betty takes a pair of scissors and slices up her conservative work dress into a cocktail dress.
- Upper-Class Twit: Monty is quite dense—managing against all evidence to convince himself that he has "it", cluelessly letting Betty manipulate him into an introduction to Cyrus, stupidly breaking up Cyrus and Betty, and topping it all off by not paying attention and ramming another boat when placed behind the wheel of Cyrus's yacht.
- The Vamp: Betty sexes it up in order to extract a marriage proposal from Cyrus on the yacht.