The money is used for the various purposes such as the charity for the poor orphanage, the promoters' department or club, and so on, depending on the aim of the promoters. Thus, every day bar or day cafe has a title such as 'A day bar for the 30th years anniversary of the department of Biology in Sogang University'. Actually the profit is not so high as you might expect, because almost all of the guests are the close friends of the promoters. Which means, the number of the guests are limited. The strangers don't come to the day bar and the day cafe, because as I've written above, it is more expensive than the ordinary bar or cafe.
Nobody drinks too much, everybody drinks adequately.
The merit of being the hosts It is really fun to be the hosts. In the process of helding it, the members of the hosts will find themselves to be more close to each other. It is true that being a promoter is more difficult than being a guests. But, it is also true that being a former is more fun and valuable. Once you hold the day bar and the day cafe, you'll surely find out how precious experience it is.