Same username/email for merchants and affiliates

I think is a good idea, possibility to signup as merchants and affiliates with the same username/email.

This because some merchants account can be also affiliates, but this is not possible with a unique username/email.

For example:

I'm the administrator of my affiliate program, so i'am signup as merchant, but i'm also signup as affiliate, to check program, promote campagin on other web site... and i can't signup as merchant and affiliate with the same username/email.

Same thing if a merchants (not admin as me) want to check campagin result (in merchants panel) and promote also some other campagins as affiliate, can't signup with unique email.

What's we think about?