Because yield is the proportion of a company's annual dividend payout relative to its stock price, it's not unusual to see stocks that offer big yields also trading at relatively low price-to-earnings multiples. However, a stock isn't necessarily cheap just because it has a big dividend and a P/E that is below the market average. Instead of having unquestioned devotion to earnings multiples and yields, dividend investors will typically be best served by seeking out businesses that are also poised for the types of continued success that will allow payouts to keep flowing and growing. Within that mold, three Motley Fool contributors have identified Brookfield Renewable Partners LP (NYSE: BEP), AstraZeneca PLC (NYSE: AZN), and Hanesbrands (NYSE: HBI) as stocks with big yields that also trade at substantial discounts relative to their long-term earnings potential.