Supreme Court Rules For Samsung in Smartphone Fight With Apple (reuters.com)
The Supreme Court on Tuesday sided with Samsung in its high-profile patent dispute with Apple over design of the iPhone. The justices said Samsung may not be required to pay all the profits it earned from 11 phone models because the features at issue are only a tiny part of the devices. From a report on Reuters: The justices in their 8-0 ruling sent the case back to the lower court for further proceedings. The decision gives Samsung another chance to try to get back a big chunk of the money it paid Apple in December following a 2012 jury verdict that it infringed Apple's iPhone patents and mimicked its distinctive appearance in making the Galaxy and other competing devices. The court held that a patent violator does not always have to fork over its entire profits from the sales of products using stolen designs, if the designs covered only certain components and not the whole thing.
You're close, but it isn't the incremental profits as it is with other types of IP; here it is 100% of the profit directly attributable to the component. So it doesn't matter how much profit they made, or how much less they would have made had they not infringed.
What matters is the profit that they made from the physical component that infringed. It doesn't matter what the differential would be if they used something else. Unfortunately for Apple, the design patent covers primarily the plastic bezel, for which Samsung probably doesn't even have any profits, and the software screen layout, which is software, and likely don't have any profits from the software either.
The reality is that design patents aren't as useful as Apple claimed; on a decorative item, which is what they're intended for, they offer a lot of protection because the design actually is the value; a decorative plate is the typical example. Complex items that are mostly functional aren't well protected by design patents, because most of the device is functional and by definition isn't covered, and you're not going to get paid for the functional components just because the case copied your case. If a regular functional-but-ugly smarthphone cost $5, and the one with the fancy design code $500, as is the case with decorative plates, then it would make sense to protect it that way.