If you're outside of North America, Latin America, and Japan, AdSense referrals will be retired.Now you will agree that "retired" is a nice word for getting "rid off".
This means that all of us guys outside the three regions/ country will have to take down the codes by the last week of January.
The reason given by Google is that Adsense referrals haven't performed as well in regions outside the ones given above.
For more info read their post: "Upcoming referrals changes".
BTW, this is my first post using my new "PayPerPost PC" that came today morning.