They dedicated a tap ( cryptobetting) on their wallet to 1xbit.com and they also have a promotional code that gives 125% on first deposit to new users who register using the code "Mycelium", they are not only paid to advertise but it seems like they are in partnership with 1xbit.com.
Judging by how the above image URL looks like, it's very likely they partnered up with 1xbit.
