Emirates Skywards program is one of those whose miles have hard expiry date. The airline started selling its miles (read more here) and just realized that it could make some money by reinstating expiring miles too.
Members can extend the validity of their expiring miles up to 3 months in advance or within 6 months of their expiry for 2 cents per mile.
You can access Emirates page for Skywards miles extensions/reinstatements here.
Considering that most airlines sell their miles for less during frequent sales than what Emirates here charges to reinstate/extend theirs, I cannot say that this would be a deal.
It may make sense if you have good use for them such as upgrading from economy to business or from business to first class.
Couple of months back, I used my about to expire miles for one EasyJet flight and got less than half a cent per mile value out of them compared to cash fare on the same flight.