A woman’s love affair with skin care products—from those touting anti-aging benefits to natural/organic lotions to those containing a desirably high SPF—is a fickle one. About 33% of women who switched skin care brands during the past 12 months have done so just because they wanted to try something new. Another 16% of women ages 18-29 switch brands regularly not because the products no longer work for them, but simply out of boredom. So, how are the hundreds of mass-market and prestige skin c...