Not entirely true, although I do not know Dplay myself, I think they still have reputation in the industry. Not because they don't have an announcement thread here, they are already a non-reputable casino. Some casinos are highly reputable even if they are don't have any ann thread here in Bitcointalk. The world is way much bigger outside this forum.
This is the advantage of having an ann thread in the forum. Moderators and staff of a casino like Roobet always monitor their users feedback and act accordingly for the satisfaction of its users as long as it does not breach their contract agreement.
but on social media it's harder, easier to fake, usually done just to farm engagement
I prefer not joining on social media.
But I do not think Roobet will fake their social media giveaways, what is it for them to gain if they fake it? They have been hosting several contest already and they always deliver with integrity. Why not make a try on this Social Media promotion of Roobet, who knows maybe you will be the next lucky person to win.