It worked fine for me. Took a few days to receive the code but it came. I sent 2 invties, one to my wife's email account and one to a friend and they both receieved the $25 off code.
Also, I read in a thread somewhere on this site about having to have a code for each individual and the n having to book the flights individually. When I put in my code for 6 people it took the $25 off every person's ticket.
Hope this helps.