In a previous article I outlined three basic types of dividend growth stocks. One group of stocks included companies which are rapidly growing earnings through expansion. This could be through organic growth, acquisitions or through a combination of both. Most of these enterprises tend to reinvest a large portion of their earnings back into the business, which helps them to further generate higher profits. As a result, these companies tend to yield less than the average yield for S&P 500. In addition to that, because of their strong earnings growth, investors typically bid up these shares and they trade at rich valuations.