Spark is exploring new ways to deliver video entertainment to customers, but Lightbox's chief executive says it won't be affecting their product.
"Lightbox will remain exactly as it is," chief executive Kym Niblock said.
Spark's half-yearly financial announcement to shareholders said the company would continue to invest in media, and would move towards an open platform approach for video content.
Niblock said Lightbox was "going gangbusters" and would continue to buy content.
Spark managing director Simon Moutter said the company would be fine-tuning the content being bought.
"We have an appetite to continue to be the buyer of rights for some content and be more selective about the type of content we'll buy," Moutter said.
The company had a desire to move away from what Moutter called "a long tail of unexciting content".
Niblock said Lightbox was "evolving" as the industry changed and was looking into how to get the content balance right.
"One of things we've been working on over the past year how to make sure Lightbox can stand up inside the Spark machine and be a big part of Spark... that frankly just means better offers for customers."
Moutter said Spark wants video entertainment to be available for as many customers as possible.
"That means shifting to a platform with more flexibility.
"It's early days it's a choice we've just made and we've got quite a bit of work to do to put that into affect."
Lightbox was launched by Spark in 2014, and offers exclusive access to shows like Better Call Saul, Outlander and Flesh and Bone.
The product ran into difficulty late last year when a software update from Apple voided its compatibility with Apple TV Air Play.
Today its website showed a message saying a fix for the glitch would be available in "coming weeks".
In Spark's announcement yesterday Moutter said the mobile growth had offset the declining sales of the fixed-line business to lift profit by 9 per cent in the six months to December 31.