Like any new technology, LED lighting must demonstrate a compelling value to buyers before it begins to win sizeable market share from the incumbent technologies it will replace. Over the past decade, research and development have yielded impressive improvements in the cost, color performance, light output, efficacy, reliability, lifetime, and manufacturability of LED products. Looking at LED packages specifically, the cost in dollars per kilolumen ($/klm) has been declining rapidly since 2005 at a rate of around 20% per year. As a result, LED lighting products have become competitive in almost every lighting application, but there is still room for improvement. Despite the rapid pace of its development, LED lighting has not yet come close to achieving its full potential. Significant work remains to be done to further improve performance and reduce costs.