Is a 15% yield better than a 6% yield? If all you care about is size, sure. But if you are trying to live off of dividends, the answer is no.Almost by definition, income investors pay a lot of attention to dividend yield. There's nothing wrong with that, but it shouldn't be the only thing that an investor considers. The company behind the dividend is equally important to think about.This fact is highlighted by a comparison of AGNC Investment (AGNC 1.47%) and its 15%-plus yield and W.P. Carey (WPC 1.85%) and ...