Disney Consumer Products' VIP Halloween EventMore than 3 million Disney Frozen Elsa and Anna role-play dresses have been sold at Disney Store and mass retailers in North America in less than a year, according to Disney Consumer Products. Elsa and Anna also led costume sales by double digits at all Disney Store locations in North America. In addition, the National Retail Federation’s 2014 Halloween Consumer Top Costumes Survey said that an estimated 2.6 million children planned to dress up as one of Disney’s Frozen characters this Halloween.

Since Frozen’s release last November, Disney Publishing Worldwide and its licensees have published more than 800 Frozen print titles globally and more than 35 e-books in the U.S. The Disney Karaoke: Frozen app has reached the No. 1 spot in the iPad Entertainment Downloads category in more than 100 countries worldwide, and the Disney Frozen: Free Fall app is Disney Interactive’s top-grossing and most downloaded app of the year.

A Wall Street Journal article published on Tuesday says that a real sibling rivalry exists between Elsa and Anna products—with one sister clearly winning. According to the article, Disney marketing executives expected the sisters to be equal in popularity, and were caught off-guard by an overwhelming preference for Elsa, who outsells Anna in dolls, toys, costumes, and other items. In turn, Disney makes sure to stock Elsa items in stores: for example, about 10 percent more Elsa dolls are stocked than Anna ones at Wal-Mart. Although Anna is No. 2 to her sister, she still ranks above all other Disney princesses.

To help combat the sibling rivalry, companies are selling dolls with both sisters, and sales data from last holiday season shows that girls want to play with dolls or role-play with costumes featuring both characters. Companies such as Jakks Pacific—and retailers such as Toys “R” Us—are making and selling products, respectively, that have both sisters involved.

Meanwhile, toymakers view Olaf, the sweet and quirky snowman of the movie, as appealing to girls, boys, and grown-ups.