Online bookseller Amazon is getting into the DNS business and has released Amazon Route 53, which is a programmable Domain Name Service. Using the system you can create, modify, and delete DNS zone files for
any domain that you own and can easily add and modify DNS entries in response to changing circumstances.

It is possible to create a new sub-domain for each new customer of a Software as a Service (SaaS) application. DNS queries for information within your domains will be routed to a global network of 16 edge locations tuned for high availability and high performance.

Route 53 also includes something called a Hosted Zone which is equivalent to a DNS zone file. It begins with the customary SOA (Start of Authority) record and can contain other records such as A (IPV4 address), AAAA (IPV6 address), CNAME (canonical name), MX (mail exchanger), NS (name server), and SPF (Sender Policy Framework). You
have full control over the set of records in each Hosted Zone.

Route 53 will cost you $1 per month per Hosted Zone, $0.50 per million queries for the first billion queries per month, and $0.25 per million queries after that. Most sites typically see an order of magnitude fewer DNS queries than page views.