I'm not really aware of anything on WAX that offers any kind of staking rewards, but they have some good email promotions.
I got one of the coveted golden *Fryin' Brian" GPK cards as a reward for just signing up for early access. So my best advice is sign up with your email before the sale and you may get lucky.:)
These guys really know blockchain. They've been doing the Worldwide Asset Exchange quietly for years. I think we can expect one innovative thing after another from WAX. I'm extremely excited about the upcoming KOGs (Keys to Other Games). https://wax.kogs.gg/ (they're doing an early access email giveaway too)
Sweet! All signed up :)