Especially in the popular music world , such tours can become large-scale enterprises that last for several months or even years , are seen by hundreds of thousands or millions of people , and bring in millions of dollars ( or the equivalent ) in ticket revenues .
Especially in the popular music world , such tours can become large-scale enterprises that last for several months or even years . They are seen by thousands or millions of people , and bring in millions of dollars ( or the equivalent ) in ticket revenues .