SWANSEA Council and the Welsh Government commissioned Cardiff University to carry out the study in the football club's impact on the local economy.
The university's Welsh Economy Research Institute was asked to not only look at effects of the promotion, but spending patterns of the club and how it supports the local and wider economy.
The spending patterns of home and away supporters were also looked at.
Swansea Council also asked for a series of recommendations on ways the economic benefits could be maximised.
As part of the data collection, 740 fans of the club and visiting clubs filled out questionnaires about their spending habits. The study, for example, noted that 44.1per cent of away fans reported staying for a night when visiting.
The club also provided information on its spending habits, broken down by item and location.
A multiplication tool was then used to access the overall activity.
From the figures, it was worked out that of the £58 million generated by club, £55 million stayed in Swansea.
In conclusion the report said the effects of the club on Swansea were significant.
It added: "While the club itself is now a major employer in the area, the study reveals that the club actually supports more employment indirectly than directly, particularly through the impacts of visitor spending."