Technology develops at a really fast pace these days. It's hard to predict what's going to be a massive, world-changing success, and what's just going to be completely forgotten in about a year. In the case of these 10 gadgets, they had all the possibility to be the former, but were ultimately the latter.
Back when 3D video games were starting to become a big thing, Sega decided to get a leg up on the competition by releasing the Sega Saturn ahead of Sony's new PlayStation console, as well as the Nintendo 64. Unfortunately, it was way more expensive and had a tiny game library, meaning it never caught on. In fact, it was the start of Sega's big decline as a console maker.
Remember when we all thought we were going to be rolling everywhere on two wheels? Turns out that's not gonna happen when 1) cities aren't designed with architecture in mind for these things at all, and 2) when the stupid thing is priced at $5,000. Guess the mall cops are happy though.
Back when choosing your browser was a really big deal, Netscape was one of the names we thought would never go away. It made big waves by winning an anti-trust lawsuit against Microsoft, but then interest in the company just kind of fizzled.
Nintendo Virtual Boy
Back before 3D and virtual reality were a big deal, Nintendo decided to try their hand at both with this weird console that had a screen for each eye, creating a 3D effect. Unfortunately for them, it was expensive, heavy, and caused people headaches if they played it for too long. It barely lasted a year at market, and remains the company's biggest failure.