First spotted on Cheapies, then I found an article on NZ Herald.

https://www.skinny.co.nz/broadband 

Terms & conditions:

The six months free broadband offer (“the offer”) applies to your first six months base plan charges on your new Skinny Fixed Line account. The offer is only available to customers who do not currently purchase broadband from Skinny and have not had broadband with Skinny within the last 90 days. The offer is available for a limited time only.

Offer applies to new Skinny customers signing up to any of the following plans, on a 12-month term:
Unlimited ADSL
Unlimited VDSL
Unlimited Fibre 30
Unlimited Fibre 100
Unlimited Fibre 200 Cantab
Unlimited Fibre Ultra

The offer includes a free modem and standard broadband connection for ADSL, VDSL and fibre customers. Non-standard installation charges apply. Modem shipping and handling fee applies.

If you leave Skinny before the end of your 12-month contract, an early exit fee of $199 will apply if you leave in the first 6 months and $99 of you leave in the second 6 months. The offer is subject to change without notice.

The offer will be applied to your Skinny account as a credit for 100% of your base plan charges.
The offer does not include any additional services which will be charged at full price, including during the first six months of your new Skinny plan.

This offer may not be combined with any other “new customer” promotional offers. It may only be combined with other publicly available offers on the Skinny website (an “other offer”), provided you are eligible for the other offer at the date you sign up, the other offer is not a ‘new customer’ offer and the combination of the other offer and this offer is not prohibited in the terms of the other offer.

Broadband not available everywhere and speeds vary. Local Fibre Company terms apply if you have a fibre connection. Skinny's Broadband Customer Terms and Conditions apply to all Skinny broadband plans.