If all sign campaign participants have the same motto as you, this will really help the casino and help themselves for possible longer campaign. This is what we called as mutualism symbiosis but unfortunately, maybe there is less than 10% of gambling sign campaign participants who are willing to spend some of what they earn to play on the casino they promote. We can simply look at the fact from any bitcointalk contests, the number of participants is so low compared to the number of forum members who are participating in signature campaign by casinos.
Yes, it should be like that, participants can contribute, not only to meet the payment requirements that they will receive when they are in a particular campaign, but they also provide something useful such as game information and so on.
But on the other hand, you can't blame something like this, because the person himself should know his position. Only playing a small part of what is obtained is also not a loss, especially if we really like to gamble and make gambling a place to have fun.
In which part I blame it? I said that it is just an unfortunate thing to happen in this forum and it is a hope to see most of them will be like Beparanf. No need to do exactly the same as what he did but at least do contribute to the casino they promote although with something like few percent of what they earn every week. I know it is not mandatory and people are free to do anything with what they earn but showing real contribution especially if there is competition/contest/or giveaway that is requiring them few dollars only will give much better outcome for both the casino and the participants.