Ugh. Don't even get me started. :|
It's braindead marketing schemes like this that perpetuate the myth that "Premium" gasoline is somehow better than "Regular".
It is not. Period. The only difference between the two is the octane rating.
If you use Premium and your engine wasn't designed to use premium, you are simply throwing 20 cents a gallon away.
Infact, many contend that it is flat out bad for your engine. Using Premium where Regular is recommended can increase the rate of carbon buildup inside your engine in some circumstances.
Basically, just don't do it.