A particular form of Viral Marketing.
You have a science fiction movie coming out. What can do you do to promote it that goes that extra mile?
You do In-Universe Marketing. You post "found" documents from within the universe. A "NBS Nightly News" broadcast from 1972 in your world? Great. Advertising a drink from your setting? Yup. Showing a half hour of dull security camera footage with maybe thirty seconds of profoundly disturbing stuff going on? Perfect. The diary of one of the characters, with pages torn out? Synergylicious!
Distinct from the Alternate Reality Game in that there is no 'game', per se. Rather, all there is is the document. Websites that use In-Universe Marketing are usually Logging onto the Fourth Wall.
Not all Viral Marketing qualifies as In-Universe Marketing; the product being advertised must be fictional, and the "found" document must be set in said universe.
Examples should go under Viral Marketing; this entry just defines the term.
