> Phone number for a non-traveller, is pretty static and unlikely to be changed by the user often. However Email is more disposable I entirely disagree. Even

> Phone number for a non-traveller, is pretty static and unlikely to be changed by the user often. However Email is more disposable I entirely disagree. Even without traveling outside the US - my US phone-number has changed several times (change of carrier etc.); while it is possible to spin-up and shutdown email accounts (e.g. dummy accounts for services requiring registration) -- by this time most individuals should have a single serious account (and a larger percentage in the future): online bank statements, online bills, online shopping -- do you really not have a single primary account?