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 [[Watchmen (film)|"NBS Nightly News" broadcast from 1972 in your world]]? Great. [[Idiocracy|Advertising a drink from your setting]]? Yup. [[Suzumiya Haruhi|Showing a half hour of dull security camera footage with maybe thirty seconds of profoundly disturbing stuff going on]]? Perfect. [[Twin Peaks|The diary of one of the characters, with pages torn out]]? [[Crunchtastic|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.