How to make your product unique

I have been asked by prospects "So what makes your product unique"?  And I struggled early in my career for an answer to this question...knowing it might be asked by the next prospect.  And then I realized...even if the next prospect did not ask the question...he/she would be thinking it...or should be thinking it...so I developed a presentation that answered the question before they asked and won points for being insightful.  So...what makes your product unique?  You may have an answer to this...but if you struggle...it is understandable.  If you pick any one feature...you are likely to find at least one other competitor that has the feature.  What makes your product unique is that you have done the investigation to find out what problems the prospect has...and you have identified features that solve those problems...and it is the combination of several features that you know can be applied to solve his specific business problems that is unique.  And you can actually state this.  Example: "You are probably wondering what makes my solution unique?  It is the application of a group (A, B, C, D, E, F, G) of features and benefits that you won't find together from any other vendor. The fact is that feature A may be in one competitor's product and feature B may be in another vendor's product...but your product is the only one that has all the features in a group.  Good Selling!