Bloodborne demo would probably put people off if its like the Souls games. If I was furst thrown into a Souls game with 40 minutes to play, I wouldn't have a clue what I was doing , and would probably give up. Demon's thrived on word of mouth I think, and its accepted that they can take a while to get into if you're not used to them.
@Blablurn, TLoU was only 18 months ago. UC4 will be boss (sequel, granted), and I have faith in SSM. Not sure I want a new Infamous, Second Son was worse than either of the first 2 despite its incredible graphics. Maybe Guerilla can do something good with their new project, I get the feeling they've run out of good ideas for Killzone.