This from an article published last year by a London writer:
http://www.cityam.com/261493/jacksonville-jaguars-plan-increase-london-presence-building
Jags senior vice-president for international development Hussain Naqi told City A.M. in September, before the team’s most recent visit: “We very much view ourselves as London’s team and, the way we have been embraced by Londoners, we think that that is a reciprocal view.”
Despite that success, the Jaguars say there are no plans at this stage to increase the number of games transplanted to London or to move here permanently as the NFL’s first overseas franchise.
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American football is a novelty in London. I just don't believe a team will locate there permanently.