Are they meant only for the Twitter followers to grab those giveaways as not all gamblers are following the gambling Twitter handle and some may rarely visit Twitter???
They are giving away on Twitter through these giveaway and promotional tweets but this doesn't mean it's meant for Twitter users only as you see they have huge following and many are platform gamblers also.Suppose they give free spins or codes you need to redeem it on duelbits casino only.So they are for all but only few who are lucky and active will get it.
This is the crypto gambling industry and I believe almost all gamblers who are also crypto users have a Twitter account because there are always lots of updates on all things cryptocurrency including crypto based casinos.
Duelbits is a fairly established casino and has a lot of customers so their official Twitter account already has more followers and this is why Duelbits uses Twitter as a place to promote and share various bonus codes that are held.
I'm sure all Duelbits customers know this so they will continue to follow the updates provided via Twitter to get what they want, especially not only Duelbits but several other casinos must also do the same thing.