Signing in, and the two kinds of account
Why a buyer account and a contributor account are separate.
A buyer account licenses images, keeps boards and holds your download history. It is the same login you use for Listn Music.
A contributor account uploads and sells work, and has its own studio. It signs in separately, because plenty of people do both and the two need to stay apart for payment and tax reasons.
If you want to do both, create each one with the same email. They stay separate accounts; you simply sign in to whichever side you need.