A business model is how a company earns its money and how much of that money it keeps. Three plain questions can explain almost any of them.
The answers are in the company's annual report, the Form 10-K. The SEC calls its "Business" section "a good place to start" for understanding how a company operates.[S1]
Who pays the company?
Start with whoever hands over the money. That is not always the person using the product.
Meta is the clearest case. People use its apps, but Meta says it generates substantially all of its revenue from selling advertising placements to marketers.[S3]
Many companies have more than one payer. Amazon's 10-K lists consumers, sellers, developers, enterprises, content creators, advertisers and employees as its customer sets.[S4]
What does the company sell?
Name the thing being paid for, in everyday words. "Ad space in apps" says more than "marketing solutions", and "electric cars" says more than "mobility products".
The SEC says Item 1 of a 10-K describes the main products and services.[S1] The notes to the financial statements can also split revenue by type or by segment.
A segment is a part of the company that it reports on separately. Amazon reports three: North America, International and Amazon Web Services (AWS).[S4]
Its note on segments also splits sales into groups such as online stores, third-party seller services, advertising and subscriptions.[S4]
What does the company keep?
Revenue is what comes in, and it is not what the company ends up with. The SEC's guide says the income statement shows revenue and ends at "the bottom line": net profit or loss.[S2]
Net profit margin turns that into one number: net income divided by revenue, shown as a percentage. The SEC's guide works out operating margin the same way, from operating income.[S2]
Meta's 10-K, for example, lists net income as a percentage of revenue.[S3]
Margins differ a lot between kinds of business, so a gap between two companies is context, not a verdict. A store that resells goods carries the cost of those goods, for example.
See it in real companies
Net profit margin at companies on Cityfort
5 companies on Cityfort, listed A–Z (not ranked).
From each company's filings, as cited on its Cityfort stock page. These figures change when a stock page is updated.
Net income can also include items outside the main business. Amazon's other income for fiscal 2025 was mainly gains tied to its investments.[S4]
Operating income comes before such items, so the two lines can move differently.[S4]
What do the three questions look like at real companies?
Each answer can fit in one sentence. The figures below come from each stock page and update when that page does.
Meta. Marketers pay Meta to show ads to people using Facebook, Instagram and its other apps.[S3]
- Largest segment: Family of Apps: 98.9% (1 of 2 segments) (FY2025)
- Net profit margin: 30.1% (FY2025)
- More detail: who pays Meta
Amazon. Shoppers buy goods in its stores, independent sellers pay it fees, advertisers buy ads and organizations pay for AWS computing.[S4]
- Largest segment: North America: 59.5% (1 of 3 segments) (FY2025)
- Net profit margin: 10.8% (FY2025)
- More detail: who pays Amazon
Tesla. Tesla designs, makes, sells and leases electric vehicles, plus energy generation and storage systems.[S5]
- Largest segment: Automotive: 86.5% (1 of 2 segments) (FY2025)
- Net profit margin: 4.0% (FY2025)
- More detail: who pays Tesla