Would provably love to see that since more competitions means the community will became more alive for participating or speculating about the particular contest they have done. And so far Roobet management is doing good with that since for example they really manage to have a good run then able to prolong the art contest that's why there's an interesting things to browse up then see the submissions made by people. Also speculate the winners since there's exciting prizes await for lucky winner of the contest.
If they could able to launch a new contest then its good really good to see that. But they should think about a contest that majority of people could participate since like art contest not everyone have talent to draw and there are limited people could able to join in that contest.
I would say they should stop with contests because I never really found them all that profitable if you ask me. Don't get me wrong, it is not impossible, it can be done, I am just saying that for marketing purposes, considering how much money they are spending, I think there could be better ways to spend it. Hell, if they just do "the person with the most wagered this week, will get this money", that may cause people to wager more, and it would directly mean more money for them, could even recoup all the money they would reward.
I do not understand your position on how you concluded that there is no benefit from the competitions they conduct and that they must stop doing so and look for alternative marketing plans, even though these campaigns have been held for years and huge budgets are allocated to them, which confirms their effectiveness. As far as I know, Roobet does not conduct any marketing campaigns outside the forum, and all (or most) of its strategy depends on the bitcointalk community. I agree with you in suggesting that they can diversify advertising plans, but not by changing a successful one.