In some cases, the vision behind a breakthrough was prescient but the technology of the day was not the best way to achieve it. Social TV (featured on the list [of MIT Breakthrough Techologies] in 2010) is an example: Its advocates proposed different ways to tie together social platforms and streaming services to make it easier to chat or interact with your friends while watching live TV shows when you weren’t physically together.
The DNA app store (from the 2016 list) was selected by Kaleigh Spears. It seemed like a great deal at the time—a startup called Helix could sequence your genome for just $80. Then, in the company’s app store, you could share that data with third parties that promised to analyze it for relevant medical info, or make it into fun merch. But Helix has since shut down the storeand no longer sells directly to consumers.
Privacy concerns and doubts about the accuracy of third-party apps were among the main reasons the service didn’t catch on, particularly since there’s minimal regulation of health apps in the US.
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[U]niversal memory (from the 2005 list) … was for one memory tech to rule them all—flash, random-access memory, and hard disk drives would be subsumed by a new method that relied on tiny structures called carbon nanotubes to store far more bits per square centimeter. The company behind the technology, Nantero, raised significant fundsand signed on licensing partners but struggled to deliver a product on its stated timeline.
Nantero ran into challenges when it tried to produce its memory at scale because tiny variations in the way the nanotubes were arranged could cause errors. It also proved difficult to upend memory technologies that were already deeply embedded within the industry and well integrated into fabs.

