There are several problems with retail and digital comparisons.
- Digital products often sell for lower prices, so units can stay the same while revenue drops.
- Digital products sales results are often reported without regard to regions, so knowing what's going on in the U.S. can be hard to discern from what's going on the UK or Germany or...
- Most companies are relying on survey results for their digital reporting. We know the digital market is supported in part by whales, and survey methods are likely to have large errors as a result.
- Digital sales aren't broken out by platform, generally, so we can't know whether the Xbox 360 is giving more digital revenue than the PS3 for a company like Activision.