There are also situations where I've been forced to have conflicted bookings. This year I purchased a round trip ORF-ATL-PHX-ATL-ORF. I then decided to drive to SAN and fly back from there, so separately purchased SAN-ATL-ORF. I could not cancel the return leg of the PHX routing until I had flown the outbound leg without repricing and causing mayhem. So I had to hold the duplicate bookings and cancel the return once I landed in PHX. But there I was actually double booked on the same ATL-ORF flight because of it for weeks leading up to the flight.