President James Pallotta says the building of Roma's property
stadium will start this autumn, and discussed the project's scope.
They seem to have the right idea and their location (Rome) might benefit them commercially in addition to gate receipts if NFL teams come to play in Italy for instance.
Bayern apparently makes €40m from Allianz Arena in addition from matchday gate receipts... I don't know the details but probably from renting the stadium to 1860 Munich and other activities like concerts et al. Roma could benefit like that following the Allianz Arena model.