Are Promotional CDs Worth Less Than Original CDs?

[BachQ]

I just came across the following information on a Tripod site that addresses the question:

G003   I have some items marked "Promotional - Not For Sale".
   Is it really illegal to buy and sell these?

    No.  The record companies will occasionally rattle their sabres on this
    issue but in fact they have no legal power to prevent people from buying
    and selling marked promos.   In fact, they are well aware that most of
    the promos they issue end up being sold in the open market sooner or
    later, and often will send out "collectable" promos in bulk as a sort
    of bribe to encourage record shops and radio stations to push their
    product.  The "Must Be Returned To The Record Company On Demand" wording
    of some promo labels is meaningless; no record company has ever issued
    the demand.

This is false. If a retailer is mass-selling promos, an aggrieved plaintiff (copyright owner) can seek an injunction to enjoin the retailer from selling promo CD's.  Thus, record labels DO, in fact, have the "legal power to prevent people from buying and selling marked promos."

The fact that record labels HAVEN'T routinely enforced their copyrights doesn't mean they WON'T under the appropriate circumstances.

[GreenJelly]

I know this is an 8 year old thread, but there are new rules regarding promo cd sales which make it LEGAL to sell and buy "Promo" CDs. 

I can provide sources but welcome you do your own sources.