They have many marketing promotions as I know and even contest promotions will help to boost their popularity. Social media promotions and others also Roobet had and no wonder why they are very successful and well-known gambling casinos now.
This is a good idea for others, don't think about the profit that you have, spend an amount on promotions and it will surely have an ROI in the long run as we can see on Roobet.
They also have
Marlon “Chito” Vera UFC fighters as brand ambassadors, this is clearly one of their forms of marketing to make Roobet even bigger.
Also, this giveaway will be held again by Roobet after a period of stopping, but this time it has a longer duration of 14 days as far as I remember before it was only 7 days and after that it will be drawn.
https://twitter.com/Roobet/status/1524962642263253013