Last April, I had to fly one-way from Boston to Allentown, PA. The cost of a round trip ticket was significantly less than a one-way. Used the southbound portion of the ticket, tossed away the return since there is it was a non-refundable ticket. US would not give me credit towards a future flight purchase without charging the $75 changing fee. Mileage was only credited for the one segment that was flown. Mileage is not credited when a ticket is purchased but only when you actually surrender your boarding pass.
However, you could have the return portion scheduled for a date in the distant future in hopes you might end up flying one way back to your origination city again.
------------------
Addicted to airline miles? Check out:
The Airline Mileage Workshop
[This message has been edited by MileageAddict (edited 02-12-2000).]