The phrase "to become the next big thing" means to gain popularity, become widely recognized or accepted and achieve success on a large scale. Full definition
Business - grade tablets, those that can truly replace a laptop, are quickly becoming the next big thing in solo and small firm technology as well as in the general marketplace. (slaw.ca)
It seems that space tourism is set to become the next big thing for adventurous types with deep pockets. (techspot.com)
Due to the many companies that have invested in cryptocurrency, people are expecting that one of these will soon become the next big thing. (knowtechie.com)