Every year in August, when people start anticipating cooler days and longer nights, the vacant husks of defunct retail stores are possessed with new life. A creepy clown statue appears in the window of a former JCPenney’s; the aisles of an old Radio Shack are stocked with sexy Daenerys costumes—and above the entrance where the old store’s logo used to be, a banner shows a grim reaper lurking next to the name Spirit Halloween.

Spirit Halloween has turned seasonal pop-up stores into a multi-million dollar business. In the 2015 Halloween season, the company raked in $400 million in sales. Here are some facts about the ephemeral costume shop to bring up the next time you visit a Spirit Halloween location near you.

1. Spirit Halloween started as Spirit Women’s Discount Apparel.

Before Spirit sold fake blood capsules and Freddy Kreuger masks, it specialized in everyday clothing for women. Spirit Women’s Discount Apparel was the first business venture from California entrepreneur Joe Marver. When he noticed how much success the costume shop next door was having around Halloween, he decided to swap his regular apparel for costumes for a limited time in 1983. Sales were great, and the next year, he opened his first pop-up Spirit Halloween shop, which brought in $100,000 worth of revenue in just one month.

2. Spirit Halloween was purchased by Spencer’s in the late 1990s.

After building a business selling fart machines and other naughty items in shopping malls, Spencer Gifts entered the Halloween market. The retailer purchased Spirit Halloween in 1999 when the pop-up chain consisted of around 60 temporary locations. By Halloween 2018, Spencer’s had grown the operation to more than 1300 stores in the U.S. and Canada.

3. The retail apocalypse is good for Spirit Halloween's business.

Mike Mozart, Flickr // CC BY 2.0

The rise of online shopping has led to many strip mall staples shuttering locations or going out of business for good. Spirit Halloween is an exception. That’s partly because all the abandoned big box stores dotting highways across America amount to more real estate options for the pop-up chain. By the end of 2019, 12,000 chain store locations are expected to shutter, and landlords are desperate to fill those spaces with paying tenants. That’s good news for Spirit Halloween—and bad news for any nostalgic Toys ‘R’ Us fans who don’t like to see their childhood toy shop selling fake severed heads.

4. Spirit Halloween starts scoping out locations in November.

The pop-up stores may only be open for a few months, but keeping the business running is a year-round operation. The day after Halloween—when many customers put their costumes away and start thinking about Thanksgiving menus and Christmas shopping lists—the realty team at Spirit starts hunting down locations for next season. Even though empty retail space is more plentiful than ever, negotiating lease deals with property owners can take months.

5. Spirit Halloween has donated millions to children’s hospitals.

When it’s not trying to terrify them, Spirit Halloween does heartwarming work for kids. In 2007, the company launched a charity initiative called Spirit of Children, and it’s since raised more than $50 million for pediatric hospital patients. The money donated by the charity helps supply toys, games, art programs, and pet therapy to sick kids. And during Halloween, Spirit gets children's hospitals into the season with costumes, decorations, and accessories.

6. Spirit Halloween products are available year-round.

Mike Mozart, Flickr // CC BY 2.0

The pop-up shops close a few days after Halloween, but you don’t have to wait until next season to stock up on your favorite Spirit gear. Spirit Halloween’s online store operates January through December. That means you can start building your Halloween costume early—or you can find a non-Halloween related reason to dress up any time of year.

7. Spirit Halloween sells items for other holidays.

You may not find Christmas decorations in physical Spirit stores, but if you browse the online shop, you’ll see a whole section dedicated to holidays that aren’t Halloween. There are costumes and outfits for Easter, St. Patrick’s Day, and the Fourth of July, and the Christmas section even includes ornaments and inflatable lawn decorations. And because this is Spirit Halloween, many of the ornaments, like an axe-wielding elf and a corpse rising from the dead, come with a creepy twist.

8. Most Spirit Halloween shoppers wait until the last minute.

If it takes you all October to decide on a Halloween outfit, you’re not alone. Mary Leonard, the manager of a Spirit store in Virginia, told The Washington Post in 2018 that nearly 70 percent of its business happens in the two weeks leading up to Halloween.