Rebecca is almost the quintessential romance written by a woman and intended for a female audience (although I read it myself and have seen the Hitchcock film version several times). Since the publication of Rebecca there have been hundreds of imitations. Typically these romance novels appear in paperback with an illustration on the cover showing a young woman in the foreground and a big house behind her.
The essential ingredients in this type of novel are that a woman meets a rich man, usually in a foreign setting. He falls in love with her, marries her, and makes her the mistress of his palatial home, where all she has to do is supervise a household of servants and occasionally act as hostess at elaborate parties and dinners. She moves from near poverty to high social status. Then she discovers that her husband has a deep, dark secret. He becomes emotionally dependent upon her for love, advice, encouragement, and moral support. The deep, dark secret ingredient may not be absolutely necessary if the novel is short, but it helps to strengthen the heroine's position.
Stereotypically, I would say that most people would agree this is a novel for women. This is for a number of reasons. Firstly, the narrator is female, and her first person narrative gives us a very strong feminine perspective of the events in the novel as the new mistress of Manderlay struggles to adjust to her new life and compete with somebody that is in every way superior to her.
Secondly, it is important to realise that this novel is very much based in a number of popular fairy tales such as Beauty and the Beast and Cinderella. You have a young, naive and innocent girl in a situation of some need who is suddenly swept off her feet by a handsome and charming knight in shining armour. Although this fairy tale story line is subverted in lots of ways, the basic plot is something that would appeal more to a female audience than to a male audience.
Lastly, the majority of the narrative in this story is based around the narrator's struggle with her own self-esteem and trying to find her own identity as a woman. This is again something that might be regarded as something that would appeal more to a male audience.