All the businesses with product catalogs for example, every product can have several time series associated with it. If a business has 10k employees, you have, at minimum, 10k time series to perform employee analyst operations over. There are several hundred companies in the US with 10k+ employees. There are many more than 10k postal zipcodes in the US to perform forecasts over.

As an energy retailer, I have 10k+ timeseries.

I forecast 400k timeseries every 30minutes at work.