The  'campaign ' referred in  title refers to the donation campaign/ ICO  which was started on 18 November.

Almost all other ICOs keep the signature campaign active till the end oi crowd funding . Have got a different strategy, they are giving referral bonus oi referrals. Which means, although the sixties campaign is our, many would be keeping the signature to get referrals .
In this way, Wings would not pay signature campaign but still people would keep signatures

Actually, 1 million in referrals is a very big amount.