My colleague and I will soon launch a landing page for an upcoming product, which is basically a mobile app.
We are debating whether we should get a new domain for this product of if it won't make a difference.
Our "main" domain, the organization's one, is 6 characters long and ending with .com.
Our product's name is also 6 characters long, so our landing page would be abcdef.ghijkl.com.
Another point that was mentioned was e-mails, will it be a problem to have an e-mail like support@abcdef.ghijkl.com?
Emails with subdomains in them sure are rare, but not non-existent. Especially if you live overseas .co.uk etc. Imagine emailing mikaelmello@abcdef.ghijkl.co.uk. Pretty extreme.
But still, I see this sort of thing with .edu email addresses, often separating out the name of the school from the particular study, then the lab itself. I did something similar to this with my old 90's era domains.
I would expect the most important consideration is whether the ghijkl part is easy or well-known enough to remember instinctively, so it isn't muddled up with the abcdef part.