48 Hour codes don't appear to work anymore. Just tried one I got a couple weeks back and while it accepted the code, it won't allow me to play online or join parties. It still says I'm a free member.
This was all last night. I made a new email this morning to see if it was still working and sure enough, it's still pumping out the 160 MSPs. It's a contest, not a giveaway. Not everyone is guaranteed to win points. Just because you don't win doesn't mean they aren't handing the points out...