The best way to understand the ways that Big Tech companies do and don't compete with one another is to use the old Watergate adage: Follow the money.

Why it matters: How Apple, Google, Facebook, Amazon and Microsoft make their revenue today shapes the battles they will fight tomorrow.

The big picture: For years, the largest tech companies each had their own fiefdom where they garnered the lion's share of revenue and profits.

• While tech companies competed at the edges, they took pains — and sometimes struck deals — to steer clear of the others' core businesses.

Yes, but: Their search for growth is now leading them onto one another's turf.

• Amazon and Apple, for example, are getting more revenue than ever from advertising — the heart of Google's and Facebook's business.
• Google is investing heavily to catch Amazon and Microsoft in cloud computing.
• Microsoft, Google and Facebook each have their feet in different parts of the gaming market, with Apple and Amazon dabbling too.
• Amazon, Apple and Google each operate major subscription streaming services.
• All five are investing heavily in AR/VR hardware and systems.
• And all of them see AI as central to their future.

Be smart: Like wealthy families that have run a town for decades, these companies share a vast web of dependencies and grudges — as in the recent privacy war between Facebook and Apple.

Here's what you find when you "follow the money" for each of tech's Big 5:

Apple

Hardware — mostly phones and computers — still generates the bulk of Apple's sales. But the company has significantly diversified in recent years.

• By the numbers: Apple reported $365 billion in revenue during its past fiscal year, which ended in October. Of that, more than half ($191 billion) came from iPhone sales, while the Mac, iPad and accessories each generated more than $30 billion in revenue. Services — which for Apple means everything from extended warranties to content subscriptions — accounted for $68.4 billion, up 27% from the prior year.
• Core business: Phone and computer hardware.
• Emerging businesses: Advertising and services, including financial services (Apple Pay).

Facebook (Meta)

For all its talk of the metaverse, the social networking giant still gets nearly all its revenue from ads on Facebook and Instagram. Those cash cows have proven vulnerable via the operating systems they run on — as when Apple's tracking changes significantly dented Facebook's mobile revenue.

• By the numbers: Meta reported nearly $118 billion in revenue for the 12 months ending Dec. 31. Of that, almost $115 billion was ad revenue from its core apps. About $700 million in non-advertising revenue came from its family of apps and $2.2 billion in revenue from its Reality Labs VR unit.
• Core business: Digital advertising, social media.
• Emerging businesses: VR hardware, digital goods.

Google (Alphabet)

Google means search, but its ambitions now extend into cloud computing, where Amazon and Microsoft reign. It doesn't charge directly for Android, its mobile operating system, but a good chunk of its ad revenue comes from mobile devices.

• By the numbers: Parent company Alphabet reported $161 billion in revenue for the year ended Dec. 31, nearly all from what it calls Google Services: chiefly, search and display advertising. Also YouTube, which generated $28.8 billion in ad revenue; Google Cloud, with about $8.9 billion revenue; hardware; and "other bets," such as autonomous vehicle division Waymo, that bring in a few hundred million dollars.
• Core business: Advertising via search
• Emerging businesses: Enterprise software, cloud computing, consumer hardware

Amazon

The online retail giant has an omnivorous appetite for new businesses, including its massive web services arm as well as offline groceries (via Whole Foods), video and audio content, and medical services. Any time Amazon enters a business, it brings an enormous distribution network and access to hundreds of millions of Prime subscribers.

• By the numbers: Amazon reported more than $469 billion in revenue for the year ending Dec. 31. Most of that comes from selling physical goods, though it also includes digital goods and subscription revenue. About $62 billion came from Amazon Web Services (cloud computing), a 37% increase from the prior year.
• Core businesses: Online retail, web services.
• Emerging businesses: Advertising, physical retail, health care.

Microsoft

The dominant giant of the desktop era still casts a long shadow over the tech world, with massive revenue streams rooted both in its venerable Windows and Office products as well as a highly successful newer business line in cloud services.

• By the numbers: Microsoft reported just shy of $200 billion in revenue for the fiscal year ending June 30. While Office and Windows are still huge money makers, the company also gets significant revenue from Azure and other cloud offerings.
• Core businesses: Windows, Office and other business software; cloud services.
• Emerging businesses: Surface and other devices, cloud gaming.

Zendrive, which uses smartphone sensors to measure and improve driver safety, has announced that it's spinning out a new company called Fairmatic, a commercial insurance service that taps such data to determine its pricing.

Why it matters: By relying on actual driving experience rather than more abstract underwriting methods, the company says it can save customers 10% to 20%.

Details: The formal spinout actually happened last year, but Zendrive has kept the change in stealth mode until today, when it is announcing $42 million in Series A funding for Fairmatic.

• Also, Zendrive co-founder Jonathan Matus will become Fairmatic CEO, with Zendrive's other co-founder, Pankaj Risbood, becoming that company's CEO.

How it works: Fairmatic uses smartphones or other sensors to get actual data on miles driven as well as information on safety issues, including hard braking, sharp turns and any time spent distracted looking at the phone. Prices adjust monthly based on the data.

• The company, which has grown to 70 employees from five a year ago, is focusing on commercial drivers that aren't long-haul truckers, an area Matus said is wide open for disruption.

Between the lines: Matus said Zendrive started out working with other insurance companies, but said it often took partners two years to decide what to do and another year to actually do it.

• "We have learned that being a partner for insurance companies can be very slow and somewhat frustrating," Matus told Axios.

The gap between cybersecurity professionals' salaries in private industry and the public sector shows little sign of closing any time soon, Axios' Scott Rosenberg reports with data from labor market research firm Lightcast.io.

Why it matters: The pay disparity makes the Biden administration's giant hiring challenges — filling thousands of security and other tech-related positions in government — that much harder.

Of note: It took three years for the pay level for a typical public-sector cybersecurity worker to catch up to what a private-sector pro was making in 2019.

Yes, but: High-skilled labor in tech and other fields generally pays better outside government than in it.

• People take government jobs anyway because they want to gain experience they can't get anywhere else — or just want to serve the nation.

On Tap

• MongoDB is slated to report earnings after the markets close.

Trading Places

• Two top Snapchat ad executives, Jeremi Gorman and Peter Naylor, are headed to Netflix. The departures come as Snap is expected to announce layoffs of 20 percent of staff as soon as today.
• SAP named Lloyd Adams president of SAP North America. The 24-year company veteran has most recently served as managing director for the eastern U.S.

ICYMI

• Twitter ditched a plan to build an adult-content, OnlyFans-style service after an internal stress test found the company can't keep illegal underage content off its platform now. (The Verge)

Errata

• Yesterday's Login incorrectly referred to Elon Musk as SpaceX co-founder. He's the company's founder.

For reasons that can't be explained in Smart Brevity™, someone has managed to mount Nikon lenses onto an Apple QuickTake 150, a 640-pixel-by-480-pixel digital camera that was part of a brief foray into the space that the iPhone maker made during the 1990s.