I'm relatively new to GA, but after doing a lot of research, I still can't find exactly how to get the data I need.  I'm interested in figuring out how viewing one product leads to later purchases of other products.  For example, someone may come to my site initially to view product A, but later decide to purchase product B instead.  Therefore, even though my sales/profit are low for product A, it's actually worth much more than its own sales indicate, so it would be worth it for me to keep advertising it.  Any thoughts on how to approach this?