What incentive would this roulette offer to get players to actually use it? Tomes and gil isn't going to do it. Path of least resistance, remember? You can't toss anything in here players already have easier access to. Even increasing these rewards, e.g. offering 500 of the current tomes and 25k gil isn't going to matter if the players can't even clear the fight. From my own experience, syncing down to the primal's level, or running the current raid tier in PF has a clear rate of well under 50%, and not many players are going to want to prog outdated EX content.

EX trials already offer substantial rewards to players willing to run and clear these fights. Because these rewards are random, and have an abysmal drop rate, players are going to want to run these things unsynced if they are to group with total randoms.

.....

Now, I should also mention that hate having to say everything I just stated. Every last word. Oft I echo the status quo, but it doesn't mean I agree with it. For players like me, the challenge of clearing these fights IS the incentive. If I could group up with seven other players willing to learn, play nice, and care about performing well I couldn't care less about the rewards.

The way it would work in my own funland is the reward for clearing the roulette is simply x10 of the totem the fight drops. There would be a bonus to all players of x1 totems and a slightly increased drop rate on the mount if any player has yet to clear the fight. This would be a weekly reward system that resets along with the other weeklies. For those unfortunate to get a fight they already have the mount for, a consolation bonus of a voucher that they can exchange for a reward of their choosing will be given upon completion of the roulette. Possible items up for exchange would be MGP and Aetheryte tickets, rare dyes, and even some exclusive rewards.

The idea of the roulette is to get players in those damn fights. I envision a world where the devs are having to think about how to make content more challenging, not less; because the playerbase in general are having increased clear rates of the harder content. One can dream.