The big draw for investors with Altria (MO -0.12%) today is the stock's huge 9.4% dividend yield. But a big yield sometimes signals big risks, which is the case for this consumer staples stock today. And why most dividend-focused investors will be better off owning a far more boring company like Realty Income (O -0.32%) despite its lower 5.3% dividend yield.Here's what you need to know.Altria's got some very bad math going onAlthough Altria can boast that it has increased its dividend annually for years on ...