Jetstar says it's done its homework on the New Zealand market before unveiling its latest —and biggest— expansion in the trans-Tasman market. 

The airline's adding close to 500 thousand seats a year across five of its most popular domestic and trans-Tasman routes. 

The Australian based carrier has operated in New Zealand for 20 years. 

Jetstar Chief Executive Stephanie Tully told Mike Hosking it's always looking to open new markets and expand on existing ones. 

She's seen a shift in preference and demand for Jetstar. 

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