Executives at cable operator Charter Communications acknowledged there is a significant amount of work still to do at its fledgling mobile service, after costs heavily outweighed revenue in Q3.

The company embarked on a major marketing push for the Spectrum Mobile service during the quarter, when the service generated revenue of $17 million on costs of $94 million.

Despite accepting there is some way to go before hitting break-even, Charter Communications’ CEO Tom Rutledge noted in an earnings call that Spectrum Mobile’s debut progressed “very smoothly” during the quarter, following a soft launch in Q2 via an MVNO agreement with Verizon.

Indeed, costs in Q3 were $22 million lower than Charter Communications shelled out at Spectrum Mobile’s launch. It ended the recent quarter with 21,000 mobile subscribers.

CFO Christopher Winfrey said the company expects the mobile business alone will achieve break-even after it signs up 2 million subscribers, adding it expects mobile to grow “well beyond that”.

Cable rival Comcast, which also has a wireless MVNO agreement with Verizon, crossed the 1 million subscriber mark in Q3, 16 months after it launched.

In the recent quarter, Charter Communications added 266,000 internet customers, but lost 66,000 video subscribers. Net income attributable to shareholders of $493 million compared with $48 million in Q3 2017, while revenue of $10.9 billion in the recent period was up from $10.6 billion in the 2017 quarter.