I think it's a bit naughty charging over £8 for two tiny bits of plastic and a couple of screws without which the blind could not be installed - and then you omitted to include them in the original delivery!
Net Promoter Score is a loyalty metric used as a KPI for customer experience, measured on a scale of -100 to +100.
To calculate the NPS, we first ask customers to answer the question "How likely is it that you would recommend this company to a friend or colleague?" on a scale of 0 - 10.
Customers who answer 0 - 6 are Detractors, 7 - 8 are Passives and 9 - 10 are Promoters. The NPS is the sum of % of Promoters - % Detractors.
