Electric-shaver types need not reply.

If you shave manually and you shave every day, how often do you have to replace the blade? Is anybody getting much more than a week or ten days out of a blade before it's dull or abrasive?

My curiosity was piqued by the new ads for the Gilette Fusion blades, which claim that some people can use a single blade for THREE WEEKS. This doesn't seem possible to me.

Tell me your experience. If you're getting more than 10 days, what kind of blades are you using and what kind of beard do you have?