The general number of spectators in Swiss football stadiums has declined for several years. To solve this problem, which is of central importance for a football club, this master thesis examines to what extent user data can support fan engagement for the FC Basel 1893. On the one hand, this should prevent the decline in stadium attendance and, on the other hand, attract more spectators to the stadium. The research questions were largely answered based on literature reviews, expert interviews, and an online survey. Among other things, it has been revealed that specific campaigns have successfully prevented the decline in viewers. However, the findings of this thesis have shown that there is no clear strategy for increasing fan engagement and that the term fan engagement can be broadly defined. Various factors such as legal regulations or sporting success play an essential role. In addition, some new technologies/trends can also influence the fan engagement strategy. Furthermore, modern and up-to-date tools are also necessary to optimally support fan engagement from a technical point of view. For the clubs concerned, this means that various influences must be considered if fan engagement is to be sustainably increased based on user data.