This Lempert Report snippet indicates that:
Supermarkets that don’t yet focus on dollar stores and the trip threats they pose, better wake up. They’ve proliferated in the down economy. The top four dollar chains in the United States (Dollar General, Family Dollar, Dollar Tree and 99¢ Only) have 21,500 stores – already more stores than the nation’s major drug chains: Walgreens, CVS and Rite Aid.
My reaction to that may be Yuck, but here’s why: They don’t stock good food. If there were a dollar store for great quality produce and spices, though? Yum.