This is incorrect. NCL owns 100% of Sixthman. All Sixthman employees are NCL employees.
the "strategic partnership" wording is just marketing. Ive seen this used in other places on acquisitions.
From NCL's own SEC filings:
"In February 2012, we acquired Sixthman, a company specializing in developing and delivering music oriented Charters. The purchase price was $7.5 million, consisting of $4.0 million in cash and $3.5 million in contingent consideration. As of September 30, 2012, we completed our allocation of the purchase price, which has resulted in recording $8.5 million of goodwill and tradenames related to the acquisition."
And Sixthman's CEO is also an NCL Senior Vice President, Charters, Meetings & Incentives
but.. whatever. 🙂