As I will travel a lot between OSL and EWR the next few years, and as CO has the only direct flight between these airports, I have joined onepass. My question relates to the following offer of "welcome miles":

"Activate your OnePass account with a qualifying paid* roundtrip flight taken now through August 31, 2006 and earn 2,500 bonus miles."

Will my August 27 outbound flight qualify for this offer, or must the return trip also be before Aug 31?

In general, are miles credited as you fly or only upon completion of return flight?