What you just said is right but I've been here for more than 7 years and I can tell you that the most successful casinos/companies around here, are those who started their journey by launching a signature campaign.
Without a signature campaign, contests and giveaways are useless, imo.
Vice versa, signature campaign without contests/promotions are useless and it has been proven so many times within the past decade in this forum. I can even say that casinos without signature campaign but provide attractive promotions get better chance to survive than those with signature campaign but lack of attractive offers. The point is that both advertising and promotions are 2 important things to have for any business but the way of advertising is not only by signature campaign in this forum.
Agree to this, Providing rewards from contest makes user engage on the casino just to claim those rewards. An interested player can create a casino account without the need of signature campaign if they want compete and earn those bonus.
I believe the main goal of signature campaign is to make the casino visible to the public while contest/promotion makes user engage on the casino.
Both are important since without strong presence those contest are typically being not seen by many gamblers.