Using mystery as the core of marketing.

May 2013, Over 8 years after Yume Nikki was created, and 6 years after the last update, the fanbase was still active, and enthusiasts enjoyed their free time producing multiple fan games, animations, comics and more, however, the hopes for any new updates, or even any news about Kikiyama were dying, some people even theorized about the possibility of Kikiyama dying in a natural catastrophe in Japan.

Suddenly and without any context, a website appeared with a countdown, discussion exploded in social networks and Yume Nikki became more popular because of it. Merchandise, a web comic and a light novel were the results, the project was supposedly authorized by Kikiyama themselves, although no evidence was providen, the closure of the most intimate details of this campaign only made discussion to become more fruitful and constant.

After the inclusion of the bigger RPG Maker games like Misao or Mad Father, and a general boom of games in this engine, some months ago, two new countdowns appeared, which ended announcing the release of Yume Nikki on Steam for free, and a new project, Yume Nikki:Dream Diary, a 3D remake made in Unity, both also supposedly supervised by Kikiyama, raising it's notability to the point it is no longer the obscure game it once was, it's far away from that now.

There was obviously no clear official voices about this, but Yume Nikki was added to the Playism distribution platform in Japan on February 12, 2012, it'd be very hard for anyone in the gaming industry to think this wasn't planned and thought with the sole purpose of building up a wider audience for what already was a cult classic.

Playing with mystery and having an active community growing stronger without interfering direcly, and letting your own fans be your marketing specialists can be a great tactic, and personally I wish to see more developers doing it.

I encourage you to read more about the fascinatiing case of Yume Nikki and take what you can from this unorthodox case.