Hosted by PRWeek editor-in-chief Danny Rogers and author and journalist Richard Gillis, The Line asks "do tribes scale?" as the NFL returns to London this weekend.With special guests:Steve Martin, CEO of M&C Saatchi Sport and EntertainmentGarry Cook, former CEO of Manchester City and chief global brand officer for UFCNicky Horne, former Channel 4 American football presenter and all-round broadcast legendThe NFL comes to London again this weekend when the Baltimore Ravens take on the Jacksonville Jaguars at Wembley.Meanwhile, the big Premier League teams are becoming global brands and rugby's professional clubs are pushing hard to build support in the USA. The commercial benefits to international growth are obvious.But beyond the money men, does anyone really care?What are the comms and marketing challenges underpinning sport’s global ambitions?What’s the difference between selling a one-off event and building regular support for a new club or franchise in London? Danny Rogers and Richard Gillis will be posing these and many more questions to an invited group of experts on The Line, the PRWeek's sport podcast, available for download now. The Line is supported by Cake.