Any ideas on tracking return on investment, cookies can be tough to apply and read properly.

I dun exaclty understand the relation between tracking your investment and cookies?

Yea he lost me at hello as well :)

I assume you mean advertising investment or other traffic builders...An easy way is to have each advertisement go to a diff't URL and track it that way. We use PHP, URLS, and cookies. our index.phtml page picks the referrer (index.phtml?goto) sets the cookie, stores the keywords, and other data..if an order is placed by the person with the goto cookie, it is updated at checkout and we know how many orders were placed referred by goto, amongst other things.