Duelbits started their advertising and giveaways in social media together with their signature campaign in this forum.
If i remember it correctly , they once have 20 cents or 40 cents giveaway for the first couple of account that will use the code they are giving in instagram things that I won several times and even make it to a hundred dollars more from that bonus.
and also i am one of those players that tried Dueling in this site.
so yeah it is indeed that Duelbits are giving away those amount from the beginning and thru their generosity , still now bringing those bonuses in all forms of social media specially twitter .
Right they started the Instagram giveaways two and half years back giving away $.20 to 500 as the coupon codes which you can find here
https://www.instagram.com/p/CGdoh8DgMai/?igshid=MzRlODBiNWFlZA== and see how far they have come in these years.I came to know about them lately when they were well recognised casino on the forum and it didn't take them much time to do so.