Main Post, the private equity firm that's invested in Milk Makeup and Too Faced, has examined Dr. Dennis Gross' books and will make a minority investment in the dermatologists' skin care brand. Terms of the deal were not announced, but the object is to triple the brand's sales in three years. According to sources, Dr. Dennis Gross Skin Care is expected to have sales of $100 million this year. Following the success of brands like Drunk Elephant, which was recently acquired ...