[9dev]

Authentication on www.example.com from auth.example.net, would be a common issue, for one.

Edit: fixed the domain to actually make the point I was trying to make.

[IMTDb]

The root domain example.com is still the same here.

[9dev]

Heh. You’re absolutely right, I misspelt the domain. Point being, sometimes you have different domains that belong to the same entity and you need to bridge them; this seems strange to small companies, but happens quite often in enterprise.