The codes runs out fast so even you're active and waiting on their post its hard to get it because many users are just fast to claim it. So yes its best to have your own money to gamble, dont rely on promo codes plus its small amount only so its likely you cant play long without enough funds. But if you have time to spare then check the twitter account and wait for the post, it depends on us anyway.
Even if you are active on social media then also it's hard to claim these promo codes as you will find huge people having access to it within seconds and they can be redeemed for a limited number so you loose the chance.Have never claimed it so not indulging in them from few time and playing with my small bets only.But it's every gambler choice how they want to play.