Alphabet Inc. is changing a closely watched measure of Google’s digital advertising business and adjusting how it accounts for some private stock holdings, a move that will make reported income more volatile.
The main difference is in how Google discloses the performance of its Network business, which runs ads on thousands of third-party websites. This will no longer be reported on a “cost-per-click” basis, or how many times the ads are clicked on. Instead, Google will report changes based on cost per impression—the number of times the ads are viewed. In the fourth quarter of 2017, Google reported $5 billion in sales from network sites.