[CQ-Contest] QRZ with no call

[Larry N7DF]

I disagree that calling QRZ without a call increases the effective rate.  
My policy is to listen for one go around to see if the station gives his call.  If he doesn't give it after one more QSO I will call him and ask for his call.  If it is a dupe he has lost at least one contact and his rate is therefore reduced.
I think a lot of other people do this because I have frequently heard similar exchanges followed by "sorry QSO before".  Also he has to spend the time deleting the contact from his log so he may very well have used up the time in which he could have made another valid QSO.
The time saved by not giving the call is virtually zero since it takes about the same length of time to give the call as to call QRZ.
When I am running a pileup I close each contact by saying "Roger N7DF'.  With the exception of JAs I have virtually zero dupe calls.
That also complies with the FCC requirement that your station be identified at the close of each communication.