Time is the primary difference between a fad and a trend. Fads are fleeting. Trends develop over time altering behavior in some relatively permanent fashion. The adverb relatively is used as permanence has become, over time, far less permanent. Fads ebb and flow more quickly than trends. The best way to tell the difference, unfortunately, is in hindsight.
via Renewable Energy News – RenewableEnergyWorld.com http://www.renewableenergyworld.com/rea/news/article/2014/01/the-benefits-and-likelihood-of-solar-trends-in-2014-and-beyond?cmpid=rss