One key reason to favor databases over Excel is data integrity: databases guarantee a certain level of tidiness by ensuring that every value in a particular field will be of a single type. Volume is another consideration: Excel quickly gets bogged down or even broken by larger data sets, and databases can make performing analysis, calculations, etc. much faster. Finally, databases allow for more robust connections, enabling us to work with multiple related data sets (comparing, contrasting, joining, etc.) and to plug into other applications.