knowlesgallery/iStock via Getty Images This article was coproduced with Kody Kester. It's not a secret that there are thousands of dividend-paying stocks in the investment universe. There are probably only several hundred that are qualitative enough to be worth thinking about buying and holding for the long haul, though. That's because many of these dividend payers are unsustainable. They may have deteriorating growth prospects, elevated payout ratios, a junk-rated and worsening balance sheet, or a signific ...