The NetaTopi site has an article on a cost-price sake bar running a special promotion to celebrate serving over half a million customers.
The Nihonshu Genka Bar chain, operated by Creative Place, has an unusual business model of offering sake at cost price, with patrons charged a fee for entry.
(One of the business models covered in Strategies to attract new people to sake: cost price, enjoy with food.)
The strategy has clearly been a success in terms of drawing in the crowds, with the total number of customers for all branches breaking through the half a million mark, and Sake Genka Bar celebrated by lowering the entry fee from JPY 790 to JPY 490.
The first branch opened in Shinbashi in Tokyo in April 2015, with an entry fee of JPY 1,190. As the number of customers increased, they dropped the price to JPY 880 and then JPY 790. That makes their current entry fee just half the original one.
The bar also changed the serving sizes, also to half the original, so customers could enjoy more types of sake in one sitting. Two customers would previously order about six types of sake between them, but after changing the serving size the same two drinkers could order 12 types of sake - for the same total price.
A range of Japanese side dishes to enjoy with sake are also provided, including a multi-course menu with all-you-can-drink sake. The bars are also totally non-smoking (including vaping) to make sure customers can enjoy the aroma of their sake.
The menus list around 50 sake and mark some with the Japanese beginner driver symbol [a yellow and green V-shaped symbol] to recommend them to people who don't drink regularly, and mark others with the shop's logo to recommend them to drinkers who don't have much experience with sake.
The sake are also grouped by type, such as "balanced", "tanrei-karakuchi" (端麗辛口, light and dry), "nōjun-karakuchi" (農淳辛口, rich and dry), "tanrei-amakuchi" (端麗甘口, light and sweet), "nojun-amakuchi" (農淳甘口, rich and sweet), "selected", "interesting" and a few sake that have special offers on certain days (e.g. Aramasa's "No. 6" on days with a 6 in them).
Tokyo branches are in Shinbashi (two branches), Toranomon, Akihabara, Ueno Okamachi, Kinshichō, Jinbochō, Ōtsuka, Ikebukuro, Shinjuku, Shibuya Namikibashi, Ikebukuro Center-gai and Gotanda. There are also branches in Kanagawa Kannai, Yokohama Nishiguchi and Kawasaki.