The word 도매 (都賣) means wholesale. The 매 syllable here means sell, while 도 means capital. 도매 can be seen on various stores, both small and large. My impression is that stores that even sell cans in 12-packs consider themselves wholesalers, as the word gets overused. A related word is 소매 (小賣), meaning retail. 점 (占) means store, thus a 도매점 is a wholesale store, while a 소매점 is a retail store.
Here are some examples:
우산 means umbrella. This is not a lost-and-found, but rather an umbrella wholesale store.
According to the stairs (계단), there is an 인삼 (ginseng) wholesaler on the 2nd floor.
This store sells 노래방 (karaoke box) and other 음향 (sound) equipment wholesale. I think I took this photo in Yongsan.
You can see the word 도매 appear at least three times in these 남대문 (Namdaemun) Market signs. There are lots of wholesale dish stores in 남대문.
This place sells towels wholesale.
This place is the King (왕) of Wholesale, as far as junk food is concerned.
This place sells flowers (꽃) wholesale.