Maybe its just pure luck and shouldn't expect them to do the same over and over again for too long. I was super excited about the contest because I thought maybe some of my affiliates would gamble their money for a chance to get the ticket but I suppose that didn't happen that much.
The problem here is that many lambo for BTC websites have popped up recently which scammed their investors and ran off with their money which is why many investors are not interested in purchasing these tickets anymore. This coupled with the dormant account deletion must be the reason why your affiliate income has fallen.
It's going to happen regularly now. Any new accounts will be deleted if they haven't been used at all after 15 days.
This is good news. There is no point in leaving dormant accounts which stay inactive for long periods of time which is why I feel that this is a step in the right direction.