but even without those contingency techniques, we may take an educated guess of how long a device will be in operational. say worst case write to eeprom (save user settings) will take place 10 times a day. so (100K / 10) = 10 Kdays before the device failed, thats (10K / 365) = 27 years, quite alot compared to most devices life, professional or unprofessional devices... and that assumed you constantly boot up and close down your device 10 times a day the whole 27 years including weekend. i believe 27 years or more can be a realistic figure. with wear levelling technique, we may extend that to say 10X? = 270 years, not something even the biggest company may put their bet on, considering cash flow cycle they need in order to survive...