We got into baking our own bread some years ago and also make our own pizza, so we easily go through 10-12 teaspoons of yeast every week.  I used to buy a pound or more at the bulk food store,but it's a bit out of the way.  This is the same stuff as far as I can tell, perhaps just a bit less expensive.  We store the extra, well-wrapped, in the freezer until we need to refill our spring lid jar.