OLiS (Oficjalna Lista Sprzedaży; English: Official Sales Chart) is the official chart of the highest selling music albums in Poland. The chart exists since October 23, 2000 and is provided by ZPAV.
This is a chart of best selling music albums in the Polish media market, involving 50 matches. This overview is based on data from 233 points of sale: 227 stores of the largest retail chains in Poland: Empik (121 stores), Real (53 stores), Media Markt (38 stores) and Saturn (15 stores), two of the largest Polish internet stores: Merlin.pl, Rockserwis.pl and 4 retail stores. Taylor Nelson Sofres collects and compiles the information about selling.
References
OLiS Wikipedia(Text) CC BY-SA