Time to stock up the man cave - home tailgating is on the rise.

This is according to Mark Stewart, executive director of the Tailgating Industry Association. With more than 20 million people engaging in some form of tailgating activity, TIA estimates the annual take for the industry at around $20 billion this season. Stewart confirmed that football - including high school, college and pro - is still the sporting event most closely associated with tailgating, but added that year-round industry sales are the rule, not the exception.

Auto racing and baseball dominate the spring and summer months, and during the winter, basketball and hockey fans have taken tailgating off-site - giving up parking lots in favor of college dorms, man caves and backyards. Click here for more on home tailgating.

So while you watch those football games with family and friends over the holidays, take comfort in the fact that retailers - tailgating and otherwise - are very thankful for you and the dollars you spend.