The founder of Amazon, Jeff Bezos, wanted to name his new company "Cadabra" (short for Abracadabra). However, his lawyers kept hearing the name as "cadaver", which wouldn't be a good name for a company that was going to be selling books.
What was Bezos going to do? In 1995, the number one way that people navigated the Internet was by using Yahoo's directory which listed names in alphabetical order. Bezos thought that using a name that began with an "A" would give him an advantage over the competition. So, the name "Amazon" was selected and, as they say, "the rest is history".
BTW... Jeff Bezos' net worth is about 135.8 billion dollars. Not bad for a company that was almost named "Cadabra".