There's an interesting anecdote from Finland. A company called Copterline flew between Finland's Helsinki and Estonia's Tallinn for many years with two Sikorsky S-76 helicopters. The trip was over the ocean and took 18 minutes.
Sadly one of their copters crashed into the ocean in 2005, killing all 14 aboard. The reason was purely technical. The hydraulic steering system got stuck due to debris that had came loose from an inner coating. The copter was impossible to steer and started spinning around its axis, and spun 13 times until hitting the ocean.
It was the beginning of the end for the company. Later in 2008 they started again with two AgustaWestland AW139 copters. I was aboard once, and it was a fantastic experience. However, it boggled my mind how much even a modern helicopter vibrates. It's a wonder to me how copters can withstand the constant violent vibration. Apparently they can, except in rare cases.
In 2004 Copterline transported 75 000 passengers. If all flights were full (12 passengers and 2 pilots) it means about 17 flights a day, every single day.
Copterline went out of business in December 2008 because it was unprofitable. It's sad, because flying on a helicopter is a cool experience mortals like me usually can't experience without commercial flights.