Copy protection DRM always destroys end user value, in both convenience and robustness. When you see DRM in a business plan or analysis, it is always there to benefit someone other than the end user. Find out who, it will indicate where power lies in a content value chain.
The mere presence of DRM indicates a failure to deliver end user value. If the information object were to lose value when extracted from the bundle or service from it was derived, DRM would not be felt necessary. Therefore the presence of DRM suggests a vendor that is behind the curve, failing to find a new value to deliver as their chokepoint disappears in the digital world.
Tim is correct that DRM destroys value, but he is mistaken in his implication that it can just be Customer value that is destroyed. The 0th law of economics is that a trade only happens when both parties see themselves as gaining from it. If the Customers see less value, they pay less for the product, and its value is thereby reduced. This kind of short-sightedness is foolish enough with conventional goods, but is especially stupid with digital media, when you have no measurable marginal cost of goods and can carry over Customers' excitement into other goods.