Buy Concert Ticket, Get Full Catalog

The band No Doubt is offering purchasers of full-priced concert tickets a free download of the band's entire catalog. [Rolling Stone article.]

Assuming a band has not signed a record deal with a major ticket company (e.g., Ticketmaster), how is the deal between the band's record label and the concert promotor structured? In other words, how does the record company collect revenue for download of sound recordings?