Airpoints are useless to me as they run into the 4 digits easily with plenty of options to earn them (credit cards/transfer partners etc)
Instead, this is an open discussion about the 'best' way to retain status tier levels (status points). The whole obvious statement of "flying more" still applies but given that Air NZ have revised their earn rate for status tiers since March last year, the earning power is lower as they now reward people with what the industry terms as 'mileage runners' over people who actually do travel at a specific time slot and likely paying more.
Thus, the burn rate of a flexible time person who travels on the cheapest return flight (without checked in luggage) will earn more status points per dollar spent over someone who has to travel at a specific time slot (with checked in luggage).
Trans tasman, to slightly lesser extent, favouring mileage running. A more expensive direct flight to OZ can earn LESS status points per dollar spent over a cheaper 1 hour stopover flight (with a longer duration).
In short, it is better to book two cheap return trips (and include a stop over) than to book just one return leg (direct) while spending close to the same amount of money.
To add insult, using Airpoints earned and subsequently spent don't count towards the status points.