Twenty-one percent of Americans say they have visited at least one type of spa during the past 12 months, with both women and men expressing interest in treatments and products, according to data from the International Spa Association. ISA also said that 54% of spa goers purchased spa products during their visits. One in five female spa visitors purchased nail care products on-site. Of the 22 most popular spa treatments explored, manicures and pedicures were popular among women. Fifty-thre...