The Amazon fees of 15% of sales and the cost of merchandise mean Amazon is probably making more than the independent merchants.
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Perhaps. What do malls charge their stores?
Exactly! Plus a retail store requires heating, air conditioning, insurance, fixtures, payroll, taxes, benefits, housekeeping, on-call repairmen, a phone system, advertising, etc...
30 years ago it was 30% to 40%. They provided parking and "security". But they also had onerous rules, such as open by 9 AM every day even if there were no customers and close at at a certain hour, no earlier.
Personally, I would rather give Amazon 15%, their web site is open 24 hours without me having to be there.