Might sound stupid, but from a surfer point of view...its less tempting to join lesbian.someporncompany.com than lesbiansiteblah.com ... The surfer will think that it's not a site on it's own, but just a segment of a bigger site, and therefor that he will get less...
just my
though, but im sure it would influence how the surfer view the site...
as for meluvlesbian.com, meluvasian.com etc.. VS. a random domain for everysite...I guess it's just a matter of wheter you want to put more effort into branding the company name, or the just that single site itself... they both have advantages...for ex: Im pretty sure a lot of surfers would trust Bangbrosworldwide.com since they know that bangbus.com is quality etc...(just using it as an example)...