I know that consistency is important, specially with signature campaigns but if they do not have the funds for it then they do not have the funds for it. If the main reason was "we will do it here and there even though we have the money for it" then I agree that it is a bad idea and keep running it is better, even if you offer 50% of what others offer, you could get some people to join and leave when they find something better but you will have people at all times.
But, I feel like they just do not have enough marketing budget to do it, and that means even if they wanted to, they can't keep doing it and that is an understandable thing because it costs a lot of money.
There is a lot of speculation around this topic and the only who has the response is the Betfury team itself. I doubt that they don't have enough marketing budget for them, they probably just want to find the perfect way to see which marketing technique is the most successful for their site.