Domain experts...would the value of a domain such as tube.com be as valuable as...
 

Some of the premium adult dot coms (so porn.com, fuck.com etc.).

Also tube.com holds tremendous value in either adult or mainstream where as anything x rated will always have that limited brandness I`m thinking.

Thoughts?

No...porn gets searched way way more than tube and sums up a huuuuge industry. Tube alone is ambiguous...it can be used as mainstream or adult, but at this point if someone tells an average Joe to go to Tube.com, they would know it would have videos, but wouldn't know if it was mainstream or adult, which hurts its value. A name like YouTube even is understood mostly with branding vs. having an obvious meaning. With Porn.com however, you know exactly what you'd find there.

That said, I would think at this point Tube.com would be a mid to high 6-figure name, MAYBE low-7 to someone really rich who had to have it. Porn.com's probably worth more than what PR paid for it, like low-end 8-figures. Fuck.com probably more like low end 7-figures as its search isn't that high either and the vulgarity probably would get it filtered out more.

Interesting. I would have said that tube.com would have fetched close to 7 figures particularly in the current tube frenzy but I`m no domain professional.