American Football in the UK

This Sunday, my hometown Detroit Lions will play the Atlanta Falcons at Wembley Stadium in this season's NFL in London game. Around this fixture every year, the American media rolls out stories about how the popularity of the NFL in the UK is skyrocketing and I'm curious to know if there is any truth to this. Has the increased exposure to the NFL led to any rise in the popularity of the sport on that side of the pond, or is this just another case of the media over exaggerating the story? How easy is it to watch NFL games in the UK? Are there PPV packages or does SKY/BBC/ITV screen any games?