The bulb is rated, for lifetime hours, lumens, etc, at 130v, and when you use it at 120 or 125 volts (mine runs about 124-125 volts) then the bulbs puts out slightly less lumens, but lasts longer.
I had some 60 watt incandescent bulbs that were sold as a fund raiser for the blind (rather ironic I thought) and they were made in Hungary. They lasted for years of near continuous use. They were rated at 130 volts and I don't know whether it was that, or being made somewhere where quality meant something, but they sure paid for themselves.
Charles