We know why Apple makes computers. But why Google?

February 24, 2013, 1:00 PM UTC

Source: Asymco.com. Click once to enlarge, twice to blow up

FORTUNE — Asymco’s Horace Dediu, the master of the tech industry informational graphic, outdid himself with the set of bar charts he posted Friday comparing the revenue and operating income of Google (GOOG), Microsoft (MSFT), Apple (AAPL), Samsung and Amazon (AMZN).

The impetus for “Bits v. Bytes: Follow the money” was the announcement last week of Google’s first fully branded hardware product, a $1,299 computer called the Chromebook Pixel. Why, Dediu asks, would a Web-centric, service-oriented company like Google want to get into the hardware business? The answer is in his charts:

“Apple and Samsung,” he writes, “tower over the fortunes for software-only Microsoft or service-oriented Google and Amazon. Although all companies are growing, the value, as defined by the buyer, resides in the whole product. Putting aside all the theory, the numbers are staggering. Google, Microsoft and Amazon are skimming profits but they are not particularly efficient at profit generation vis-a-vis the integrated Apple (and increasingly integrated Samsung.)”