Spending in Dublin city centre almost halved in the wake of the riots last Thursday night.
Analysis of card transactions shows the impact of the violence on shops continued into the weekend.
It should have been one of the busiest shopping days of the year.
Instead some city centre businesses were left cleaning up broken glass and counting what stock had been stolen.
Data from Bank of Ireland debit and credit card transactions shows in person spending in Dublin 1 and 2 was down 46% this Black Friday compared to last year.
Arnotts and Penneys delayed opening that morning while other businesses took days to start operating again.
13 shops were damaged following the unrest and the impact of that continued into the weekend with spending down 27% on both Saturday and Sunday.