Alphabet Inc. (GOOGL)

When you want to know something — anything — your first instinct is to Google it. That reflex, shared by billions of people daily, is the foundation of one of the most profitable businesses ever built.

Larry Page and Sergey Brin met as Stanford PhD students in 1995 and built a search engine that ranked pages by how many other pages linked to them — treating the web like an academic citation network. They incorporated Google in a Menlo Park garage in 1998. Within five years, Google was processing over a billion searches per day. The insight that search intent reveals purchase intent — and that advertisers will pay to appear alongside relevant queries — turned Google into a money machine.

Alphabet (Google's parent company) earns roughly 77% of revenue from advertising — primarily Google Search ads and YouTube ads. The remaining revenue comes from Google Cloud (competing with AWS and Azure) and a collection of long-term bets (Waymo self-driving cars, Verily health sciences, DeepMind AI research). YouTube alone generates over $30 billion annually in ad revenue.

Google's moat is data compounding. Every search makes the algorithm better. Every click trains the ad-targeting system. Every YouTube view improves recommendations. Competitors can't replicate 25 years of behavioral data from billions of users. Additionally, Google pays Apple an estimated $20 billion per year to remain the default iPhone search engine — buying distribution that keeps alternatives invisible.

The key risk is AI disrupting search itself. If people start asking ChatGPT or Gemini instead of typing queries into a search box, Google's ad-click model breaks. Google is racing to integrate AI into search (AI Overviews), but every AI answer that satisfies a user without showing ads is revenue Google doesn't earn. It's the rare case where a company's greatest product might cannibalize its greatest revenue stream.