It's very common scam and not only in Russia. A woman splits the profits with the restaurant that charges the naive Western tourists 10x of normal bill(actually it can be without a woman trap involvment). The same can happen with a clothing store. Some guys can spend like $1000 on woman's clothes which she promptly returns and gets part of her share.
Heck even on Greek islands, many clubs had attractive ladies on payrol to get the guys in and buy drinks.
