There is no way that blockchain technology is a fad.  How much impact and use it will have is open to debate, but the ability to maintain a ledger without any need for a trusted third party is a significant breakthrough.  I am inclined to think that most of its impact will be invisible to the average person, much as the use of relational databases, or HTML5, or any number of other behind-the-scenes technologies are.  But it will have an impact, and the impact will be significant.