Dmitri's Russian Market is a store owned by Dmitri Reznikov and Galina "Red" Reznikov.
The store, prior to being boarded up and offered for lease, was frequented by Ganya, Marina, and other members of the local mafia.
This was also the location in which many mafia meetings were conducted, and where Red helped Ganya create the idea for Neptune's Produce ("Moscow Mule").
In "40 Oz. of Furlough", Red asks Piper to visit her store and report back how it is doing. Piper does so, and sees that the shop is shut and up for lease. Rather than tell Red the truth, Piper lies and says that there was a queue out the door. However, Red finds out the truth in "Mother's Day", which puts a strain on their friendship. Eventually, Red accepts that Piper was doing what she believed to be best, even though it is quite against Red's morals to behave that way.
The closure of the business coupled with Dmitri's lies about it leads Red to seperate herself from her marriage, deciding that she wants nothing more to do with her husband and wants a divorce.