S3 for DNS Failover:

• By using a failover routing policy in a Route 53 DNS record set, an S3 bucket can be used as a failover endpoint.
  • Two record sets:
    • One's alias type is ELB for primary endpoint, which is healthy.
    • One's alias type is S3 for secondary endpoint, which is unhealthy.
• This can provide an extremely reliable backup solution if your primary endpoint fails.
• And even though S3 should only be used for static web hosting, it gives you the opportunity to provide your users with some type of information until the primary endpoint is working again.
• An S3 bucket can also be used as a primary endpoint, if you just want to host a simple static site.

Note: For a DNS record to use an S3 bucket as an endpoint, the bucket name MUST be the same as the domain name.