If you persist data (e.g. store it in a database) chances are that the data will be used by managers, statisticians, stake holders etc. to analyze the workings of their software-supported undertaking to make executive decisions. This analysis can only take place by methods of aggregation. There's no one in the world who can look at a million rows of raw data and glean insight. The data has to be summed, averaged, standard deviated etc. to make any sense to a human being.
A few examples of areas where data aggregation is important:
- Public Health (CDC, WHO)
- Marketing
- Advertising
- Politics
- Organizational Management
- Space Exploration
lol. Take your pick!