Bread-Bakers v100.n002.11

Hi all--
I was just in Sam's and noticed they had bulk yeast--can this be used in a 
breadmaker?  I have been useing the rapid rise yeast that comes in a small 
jar and it is expensive.  What would be the amount to use compared to the 
rapid rise?  Also, how would you store the unused portion and how long would 
it last?  Thanks for the help.
Dara