Before revision: FPGAs are often used in limited (low) quantity production of custom made Products, and of course in Research and Development (where higher cost of individual FPGAs won't matter , and where creating and manufacturing a custom ASIC wouldn't be feasible ).
After revision: FPGAs are often used in limited (low) quantity production of custom-made products, and in research and development, where the higher cost of individual FPGAs is not as important , and where creating and manufacturing a custom circuit wouldn't be feasible ).