Why DNSimple has a dedicated status page domain
As I write this post, one of our customers, DNSimple, is currently undergoing a sustained service outage due to a volumetric DDoS attack. DNS outages can be some of the worst to deal with since there's rarely a backup provider in place, TTLs and NXDOMAIN errors live on as you struggle to get a new one stood up, and it often means hard downtime for the majority of your stack.
Luckily for DNSimple, they were smart enough to run their status page outside of their own infrastructure, and on a separate DNS provider, with a dedicated domain. As their outage progresses, they're still able to communicate with their customers via dnsimplestatus.com.
Benefit #1: Secondary DNS Provider
One of the benefits of having many customers that use each others' services, we often get to see outages cascade across our customer base. This is especially true of DNSimple since many of their customers experienced hard downtime concurrent with the DDoS attack, and also were logging in to update their status page of the outage. Unfortunately for many of these folks, their status page was tied to a subdomain, and thus was affected by their primary DNS provider.
Good Uses: metastatuspage.com, www.redditstatus.com
Bad Uses: status.meldium.com, trust.salesforce.com
Benefit #2: New SPF slots
As your company grows, there's likely going to be a contingent of 3rd party providers that will vie for your precious SPF slots. Using a dedicated domain means there's no competition, you'll have a fresh set of new slots, and any email notifications that we send out on your behalf will be DKIM and SPF validated for best delivery rate.
Benefit #3: CDN Acceleration
StatusPage.io is in the process of implementing Fastly.com as our CDN provider, and only customers that are using a dedicated domain will be eligible for the global speedup. Domains can only exist under 1 account in the Fastly system, so we're unable to add subdomains for existing customers of Fastly.
Benefit #4: No security concerns
A while back, Github wrote a great post about why they moved all user-generated content to a totally separate domain - github.io. They did so for a few major security reasons as a precaution to prevent against possible future bugs. This is quite a farfetched possibility, as somebody would have to gain access to your StatusPage.io admin credentials, your status page would need to be running on a subdomain with your session cookie scoped to the parent domain, and on one of our plans that support custom HTML/JS.
Benefit #5: No SSL corporate policy nightmares
This is more of us just anticipating issues and heading them off at the pass, but if you work for a large company with serious security concerns then getting any type of SSL certificate issued can be a nightmare of a verification process. Moving it off of your primary domain should clear all of this up.