"Marketing continues to expand, and the studios and distributors are looking for every opportunity to show upcoming movies to the most enthusiastic press and fan base, and Comic-Con is exactly that, " said David Gross of Moviereviewintelligence.com.

CNN: The long rollout: Studios build early buzz at Comic-Con

Fan Dion Jones, 27, from Caernarfon, Gwynedd, attended Wales Comic Con 2012 and returns this year to boost his 200-strong comic book collection.

BBC: Wales Comic Con convention at Wrexham Glyndwr University

Sometimes called "Comic Con's little brother, " but fiercely defended by attendees as the country's most fan-oriented convention, DragonCon had more than 30, 000 preregistered guests as of Thursday night, Carroll said.

CNN: Nerds and jocks getting along?