This PDF document is a history of Queensland Immigration and the Black Ball Line and makes mention of the Netherby.
The Netherby: the types of passengers

This page is a touch bitty as I put together what I have found about the passengers. Many were, in essence, the ten pound poms of the 1860s. Paying for a passage and bringing a trade to help populate the state of Queenland as part of the Queensland Land Assisted Package, in return for land orders. Others were self funded immigrants. All were coming to start a new life.
Data from about the types of passengers in the 1800's. Most of the Netherby passengers were classified as "assisted passengers" as part of the Queensland Land Assisted Packages.

Examples of Netherby contract tickets. These two are from an earlier voyage not the 1866 one.
The ticket of shipwreck passengers John Skerman, his wife Maria and children Ann and Walter. Held at the King Island Museum.
Close up shots of the Netherby ticket above and right. The terms and conditions of passage and the provisions supplied to each passenger. Interesting that the passengers had to provide their own utensils.
Excerpt from: The Australian People by James Jupp, in regards to the Queensland land assisted packages.
Informative slideshow about assisted immigration to Australia. Copyright Jenny Joyce.