We sell fabrics and wallpapers.  

Our leads often order free samples which we post out and then later order actual product. (2 deals/transactions on our eCommerce store)

When I follow up the cutting/sample 'deals' to make sure they have been received and try to win a conversion, I first have to manually check to make sure the 'deal' person hasn't already ordered product.  (it can be embarrassing when you follow up a sample, only to get a response that they did and have already purchased product through a second transaction).  

At the moment this manual verification is clunky and time consuming.  The quickest way is to search for the person in the search pane.  

... far better would be an indicator somewhere on the deal status panels that provides a quick visual that another deal exists that is more recent.  It can also be helpful given that when the same customer has multiple deals open concurrently, mail does not always associate with the most recent deal.  (which is usually the way we want it .. but not always).