  The main objective of the M5 competition, which focused on forecasting the
hierarchical unit sales of Walmart, was to evaluate the accuracy and
uncertainty of forecasting methods in the field in order to identify best
practices and highlight their practical implications. However, whether the
findings of the M5 competition can be generalized and exploited by retail firms
to better support their decisions and operation depends on the extent to which
the M5 data is representative of the reality, i.e., sufficiently represent the
unit sales data of retailers that operate in different regions, sell different
types of products, and consider different marketing strategies. To answer this
question, we analyze the characteristics of the M5 time series and compare them
with those of two grocery retailers, namely Corporaci\'on Favorita and a major
Greek supermarket chain, using feature spaces. Our results suggest that there
are only small discrepancies between the examined data sets, supporting the
representativeness of the M5 data.
