Prologue · Zip2 and PayPal

Before the rockets, there was a modem

In 1995, the internet sounded like a dial-up modem and hardly any shop had a website. That is where it all began: a game sold at age 12, a city map for newspapers and a way to send money with an email. Each sale paid for the next bet, all the way to rockets.

The experience · Follow the money

From 500 dollars to a rocket company

Year1983

Amounts in dollars of each year, according to Wikipedia. ↗ The bars use a logarithmic scale: each mark is worth ten times the previous one. This is not his whole net worth, only the money from these deals.

Step 1 · Zip2, 1995

Directions before smartphones

Zip2 sold newspapers an online city guide: where each business is and how to get there. To do that, the program sees the streets as a graph: each intersection is a point, each block a segment with its travel time, and it looks for the path that adds up to the least. ↗

Tap an intersection to choose where you are and a business to go to. Avenues are faster; mark a block as “under construction” and watch the route avoid it.

    A made-up city. The method (finding the shortest path in a graph, Dijkstra’s algorithm) is the classic one in any navigation app. ↗

    Step 2 · Sending money with an email
    LedgerTotal in the system: —

      Made-up people and amounts. The $10 bonus for opening an account is the one X.com gave in its early days (plus $20 for each friend invited), according to Wikipedia. ↗

      X.com and PayPal, 1999–2002

      Every payment, an invitation

      On X.com you could send money by typing another person’s email. Under the hood it is a ledger: what leaves one account enters another, and the total never changes. If that person had no account, they got an email to open one and collect.

      Try sending money to dani@mail.com, who doesn’t have an account yet. To get people on board, the company gave away money for signing up and for inviting others. In two months, X.com had more than 200,000 sign-ups. ↗

      Step 3 · Viral growth

      When every user brings another

      If, on average, each new user brings in more than one new user, the network grows on its own, faster and faster. If they bring in fewer than one, it fizzles out. Giving away money raises that number, but it costs: you have to pay every person who arrives.

      Move the bonus and watch the balance between growing and spending.

      Invites per user—
      Users after 60 days—
      Spent on bonuses—
      Cost per user—

      Illustrative model: 1,000 initial users and a 60-day campaign. Only the 200,000 sign-ups point is real data (X.com, according to Wikipedia).

      The origins in numbers
      Blastar · 1983~$500

      His first program sold, at age 12, to the magazine PC and Office Technology. ↗

      Zip2 · 1999$307 M

      What Compaq paid, in cash. Musk got 22 million for his 7%. ↗

      X.com · 1999200,000

      Sign-ups in the first two months. ↗

      PayPal · 2002$1.5 B

      What eBay paid, in stock. Musk, the largest shareholder, received 175.8 million. ↗

      SpaceX · 2002$100 M

      What he put in from his own fortune to found it, in May 2002. ↗

      Tesla · 2004$6.35 M

      His investment in the first round; he became chairman of the board. ↗

      Vision · Status

      The X.com idea comes home

      X.com wanted to be one place for all of a person’s money. In 2017 Musk bought the domain back, and in 2023 Twitter was renamed X, with the goal of becoming an “everything app”. ↗ Here is where each piece stands:

      • PayPal, today an independent companyOperational
      • The x.com domain, back in Musk’s hands (2017)Operational
      • X Money: a wallet and person-to-person payments inside XOperational
      • X as an “everything app”: messages, payments, shopping and more in one placeConcept

      Approximate status as of October 2026; things may have moved on. X Money launched in July 2026, according to Wikipedia. ↗ PayPal sold the x.com domain to Musk in July 2017. ↗