Money
Early in my career, I was contracted to create music for a number of projects by a videogame company. It was a small company. The president was very ambitious and pushed the employees to work hard. He constantly told them that if they put in their time, they would be well rewarded with much wealth. He even told a friend of mine working there, "You'll be driving a Lamborghini before you know it." Everyone believed him.
To finish project after project, they sometimes toiled away through 12-14 hour days for weeks at a time. Some even slept at the office on occasion to keep up with the impossible scheduling. They weren't happy doing this but they were loyal. Due to their devotion, the company grew incredibly and within 2.5 years time, it went public.
The president made a lot of money from this. Soon after, he left the company. He retired at the age of 36.
None of the employees gained much wealth. Some who were instrumental in the early success of the company were eventually laid off. They all still work for a living. And to this day none of them are driving Lamborghinis.