https://www.cnet.com/news/gmail-gave-google-the-confidence-to-take-over-the-world/

The success of Gmail did more than create a useful and popular product. Gmail forever changed Google's trajectory. It was the first service to demonstrate to the company that Google could dominate something beyond search. Gmail set Google on a course to touch every part of our online lives.

A year after Gmail appeared, the company launched Google Maps. It's now the No. 1 map service on the web. Google also bought Android and YouTube, the biggest mobile operating system and biggest video-sharing site. Google built the Chrome browser, which toppled Microsoft's Internet Explorer when IE was on top of the world. All those Google products have more than a billion users each. Android alone powers almost nine out of every 10 smartphones shipped globally.