Perpetuation is one of the key practical impediments to digital immortality. Anyone can purchase a domain name for one hundred years, but hosting agreements are limited to a few years at best. We have no real ability to ensure the preservation of our website, even if we own one hundred year domain names.
Constant changes in Internet browser specifications and archiving media require frequent updates to websites in order to keep them active and accessible.
Without authorized website guardians in place, such updates will not be made and the personal histories contained on the website may be lost. E.g., on 4/8/08 I heard that Susan Hurley's website had been taken down after her recent death, but this appears not to be the case. But for how long?