According to Nikkei Newspaper May 26, Kadokawa will examine all the anime videos related to their products and put ads to the videos which meet conditions below:
1. The video has a moderate length ("few minutes" they said).
2. The DVD of the anime has not been released.
3. The video does not contain other copyright holder's material.
4. The video does not insult the anime.
Mixing different anime videos are also allowed as long as all the titles are Kadokawa anime. Improper videos will be deleted.
If the uploaders show up in the video or edit it elaborately, Kadokawa will share the profits from the ads with them. For the time being, they will send a free ticket of Kadokawa movies to the contributors.

Nikkei newspaper
Some information are copied from the offline newspaper.