The document discusses how two films, Harry Potter and the Deathly Hallows Part 2 and Attack the Block, used online exchange and social media to promote themselves. It describes how for both films users posted reviews, trailers and discussion online which helped promote the films but also allowed negative comments and reviews outside of studio control. Technology played a key role in allowing this exchange. It also compares the marketing strategies, noting Harry Potter had a bigger budget and fanbase while Attack the Block targeted teenagers and relied more heavily on online promotion with limited funding.