+1I will usually get between 5 and 7 shaves out of a DE blade but some blades I can use 14 times before they start to tug.
A lot of blade longevity is dependent on how well you prepare your beard (i.e. how well hydrated and soft it is). What type of facial hair you have (coarse steel wool or soft fluffy kitten fur). The type of razor you are using. And how well you understand the proper angle the razor needs to be used at.
Changing any one of those variables can cause a blade to go south after 2-3 shaves or last a couple of weeks.