Originally Posted by
auorab
If I book a round trip flight from a European Airport to the US, and then upon returning home cancel the return ticket, would I get any future travel credit or would it just be a wash?
You will retain future flight credit, but it can essentially only be used for a one-way flight back to Europe. (Whatever itinerary you attempt to change to will be priced in conjunction with what you already flew).
Also, note that itineraries originating in Europe may include a change fee, which would be levied upon attempting to use the credit.