These aren't stupid people saying this either, well some are, but they seem to want to genuinely believe the story that hear on the news or read in the paper should be taken at 100% face value and to suggest otherwise is an act of absolutely insanity!
#1 - I remember reading in a comment section was related to the release of the Nexus 4 phone. There was suddenly a shortage just prior to launch and, understandably, some suggested it was, or could have been, a marketing move. Creating scarcity, hoping for viral hype, etc, etc. Then the "conspiracy theory" comments started and, obviously, derailed the article.
#2 - Colchester Zoo, UK. Fake lion sighting in Essex. HUGE publicity for the Zoo on all major news networks. No lion was found.
Neither, of course, were a conspiracy theory but, most likely good PR departments, the term is being thrown around for anything and everything nowadays.