"Free frog-skin belt with every purchase"
-- advertisement for Madam Malkin's Robes for All Occasions (DP1)
Clothing advertisement appearing in the Daily Prophet (DP1)
An advertisement for Madam Malkin's appearing on the front page of the Daily Prophet, offering several types of robes (including slimming and lengthening) and including a free offer to entice customers (DP1)
While the date printed on DP1 is 31 July 1998, the timeframe for these events is 1992-1993.