Mark Cuban Once Called Out The Breathometer As The Worst Shark Tank Investment He Ever Made

Entrepreneur Charles Michael Yim appeared on the second episode of "Shark Tank" Season 5 to pitch the Breathometer, with his episode airing in September 2013. The premise of the Breathometer was simple: it was a smartphone attachment that could detect a person's blood alcohol content after they breathed into an apparatus. If a person's blood alcohol content was too high, the Breathometer would tell them how long it would take to sober up. Best of all, the Breathometer could easily arrange for them to call a cab.

Yim asked for $250,000 in exchange for a 10% equity stake in his company. All five of that week's sharks were interested, including Cuban, Kevin O'Leary, Mark Herjavec, Lori Greiner, and Daymond John. In the end, Yim made an unprecedented deal with all five sharks: $1 million in exchange for 30% equity. Mark Cuban agreed to pony up $500,000 for 15%, with the other four sharks contributing the remaining $500,000 for the other 15%.

The plan was to combine Cuban's sensor technology expertise with Greiner's retail know-how, along with O'Leary, Herjavec, and John's business guidance. All five sharks were confident that it would work, but ultimately it fell apart. The reason why is still in dispute.