1. The main one: it's the cheapest region, so when people select where to run their services they pick it because "why pay more?"

2. It's the default. Many tutorials and articles online show it in the examples, many deployment and other devops tools use it as a default value.

3. Related to n.2. AI models generate cloud configs and code examples with it unless asked otherwise.

4. It's location make it Europe-friendly, too. If you have a small service and you'd like to capture European and North American audience from a single location us-east-1 is a very good choice.

5. Many Amazon features are available in that region first and then spread out to other locations.

6. It's also a region where other cloud providers and hosting companies offer their services. Often there's space available in a data center not far from AWS-running racks. In hybrid cloud scenarios where you want to connect bits of your infrastructure running on AWS and on some physical hardware by a set of dedicated fiber optic lines us-east-1 is the place to do it.

7. Yes, for AWS deployments it's an experimental location that has higher risks of downtime compared to other regions, but in practice when a sizable part of us-east-1 is down other AWS services across the world tend to go down, too (along with half of the internet). So, is it really that risky to run over there, relatively speaking?

It's the world's default hosting location, and today's outages show it.