The head of the Double Fine studio, Tim Schafer, advised novice indie developers not to place high hopes on the first day of sales of their games.
You will earn more money on the first big sale on Steam than on the launch day. Be prepared for the fact that the launch of the game will not be some amazing day on which all your dreams will come true. This is just a step on the long path of the developer, where you create cool games and get paid for your favorite thing.
game designer
Shafer added that his Psychonauts project (released in 2005) has brought him more money in the last 5 years than in the first years after the launch.
Tim Shafer also advised developers to learn how to work with deadlines and deadlines.
According to the game designer, delays in development are undesirable, but acceptable if additional time is wisely spent on useful improvements to the project.
Source: Gamasutra