Their sales spike in December Crossword Clue

 The answer to the crossword clue "Their sales spike in December" is TOYS. Toys are a popular gift item during the holiday season, and their sales typically spike in December.

According to the Bazaarvoice Network, toys and games saw the biggest growth in all areas between fall and winter. In the week before Christmas, sales of toys and games saw the biggest in-store and online holiday spike.

Other products that typically see a spike in sales in December include:

Clothing

Gift cards

Home decor

Appliances

Electronics

These products are all popular gift items, and their sales typically increase in December as people start shopping for the holidays.

I hope this helps! Let me know if you have any other questions.