That's what makes the OWL token unique and valuable. You can not only gamble with this token but at the same time, investors can stake it to earn good returns. The OWL token targets both gamblers and investors.
It is not unique what they do as Betfury was the first to launch this but it is an interesting approach. Some other sites have their own tokens but combining gambling and investing will always appeal to even more players. I have some OWL tokens but I don't play with them, just stake them and I am sure they will launch a new pool before the old one expires.
I don't know about betfury was the first to launch this or how many gambling sites have this feature but one thing is for sure that this trend is not so common yet as most of the gambling sites do not possess their own token.