Earlier quoted context omitted.
Even if that were true, it's not especially important for the end user to be familiar with the brand name "Amazon." They use its services constantly. Are they familiar with Netflix? Do they read the Guardian or the Washington Post? Maybe they use apps like Yelp or Foursquare or visit websites like Reddit or IMDb. Amazon's web services are everywhere. If you're dismissing them because you don't recognize their name, I…
Are you seriously trying to convince a non-US citizen with those services? And I fail to see how amazon hosting a few sites makes it important enough in the current web landscape to be able to be compared to microsoft/google/apple/facebook. (I bet that reddit would exist without amazon)
Just one more nitpick: Amazon does not just "host a few websites." Seriously, Amazon Web Services is a noteworthy business and is widely used -- yes at the level of those other companies you listed -- whether you believe it or not.