Even a Marxist perspective would suggest no one should work for free: workers are paid some nonzero amount below what you produce for the company. This LinkedIn article makes a good point: if your work does not add value to the corporation then why are you there occupying space? The article presents numerical evidence that working a free internship is associated with lower pay after graduation.
Do not add value to a corporation without being paid some nonzero amount below the value you add. Don’t work for free. Dare I say it, don’t be pimped – for free.
That’s my two cents (a nonzero amount).