Add source field to Customer (same as in Lead)?

Hello,

When creating a Lead, I can define its Source, to know where it came from. But this field is not available in the Customer. I will be creating a lot of Customers directly (without a Lead) and would still like to be able to define its Source.

How can it be done? Is it as simple as adding the Source field to the Customer DocType?

Thanks in advance,
Nuno