As of 10/8/2015, no live official trademarks were found on USPTO.gov for the exact term/number
In Chinese culture repeating 8's (consecutive 88's and 888's) are considered to be especially lucky.
As an ordinary 8-number domain, this number may mean little to average Occidentals (other than as an easy-to-remember cool pattern); heck, we don't fully understand the premise, either. However...
In Chinese culture, "8" is the luckiest number; "6" is also a lucky number, representing "smooth and easy" and "flow"; "9" represents longevity.
We cannot even fathom what 8.com, 88.com, 888.com, and 8888.com are worth -- probably much more than the average investor could afford.
Long repeating 8's are prized as well. In fact, 5, 6, 7, 8, 9, and even 10+ repeating 8's are commanding excellent prices these days.
Evidently, every possible string of 8's have been registered in .com, all the way up to the longest one.
Finally, repeating 8's with other lucky numerals are becoming rare as hand registrations (fresh from the registrar) and are also highly prized.
Chinese demand for numerals is HUGE and increasing each day.
* * * * *