Nearly 1 million people in the United States tan in tanning salons. In 2010, the indoor tanning industry's revenue was estimated to be $2.6 billion. Up until the 1920's, tan skin was a sign of poverty. During World War II, women used tea bags to mimic a natural-looking tan. Spray tans are in high demand today & most tanning salons offer both tanning beds & spray tanning options. Read about these tanning businesses for sale!