20-Year Prospect
Forecasts are glowing for this career, and not just because of that recent exfoliating scrub. As the economy has improved, people have slowly returned to old spending habits, including spending oodles of money on a professional skincare routine. This trend reflects the global trend in skin care, an industry that's now worth $121 billion and rising every year (source).
Just because L'Oreal is pulling in $30 billion a year doesn't mean you'll be a billionaire, though (source). In fact, the more people spend on drugstore products and do-it-yourself skin treatments, the less they'll spend on you and the other 50,000 employees in the U.S. cosmetic industry.
Sales of premium skin care products—i.e. the kinds of products you make commission off of selling to clients—are slowing down, too (source). Even if you gag just thinking about Suave or Johnson & Johnson products, you may find yourself selling them someday.
So you may not be making a ton of money, but this field of work is very likely to be flourishing in terms of availability in the next twenty years.