Beauty Startup Birchbox Is Boosting the Sales of Competitors

Each month, Birchbox ships out millions of beauty samples, neatly packaged in the company's namesake cardboard boxes. Just as the startup intends, the samples lead plenty of shoppers to buy full-sized goods from its own online store.

But Birchbox isn't the only shop benefitting from monthly blasts of body cremes, perfumes, and nail polish. Its competitors are too, according to a new study from research firm Slice Intelligence.