"tada-copy" gives a free copy to everyone. In some universities in Tokyo, this new business is getting popular. A venture company created by students has started this new business.
Normally, when you insert 10 Yen, you can copy only one page, but when you use "tada-copy" you can copy for free. The reason that it has become free is because advertisement is published on the reverse side of the copy paper.

advertisement on the reverse side of the copy paper
Currently, because the places where it is installed is mainly the university, the advertisements to appeal to students are very effective. In addition, the fact that we rarely copy both sides is one of the successful reasons.
interesting!