Ask HN: Should I get a new domain for the product I'll launch?

I've typically combined both options. The shorter domain (abcdef.com) is just a pointer to the longer one (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.

I don't think it'll make a difference. There are probably more important things to worry about.