Fitbit may lose some sleep over a putative class action challenging the advertising claims for its sleep-tracking function after the court denied the company’s motion for summary judgment in the case.

In May 2015, James Brickman filed suit alleging that Fitbit charged consumers more for a device that featured a sleep-tracking function the company claimed would allow users to track how long they slept, the number of times they woke up and the quality of their sleep. He said the $30 add-on feature failed to perform these tasks as promised.

A California federal court judge denied Fitbit’s motion to dismiss the suit in 2016 and certified California and Florida state law classes of plaintiffs earlier this year.

In the latest blow to the defendant, the court denied the company’s motion for summary judgment, ruling that the issues in the case “are replete with disputes of fact for which both sides have more than merely colorable evidence.”

For example, Fitbit argued that no genuine dispute existed that actigraphy (the science used by the device to monitor sleep by assessing physical movement) is a valid and reliable sleep-tracking method used by sleep scientists. “That is far from true,” U.S. District Court Judge James Donato wrote. “Fitbit tenders declarations, exhibits, and other materials in support of its position on that dispute, and plaintiffs do the same.”

Similarly, the defendant argued that its devices performed as represented and that the plaintiffs lacked evidence showing the devices failed to track sleep. “As an initial matter, plaintiffs have tendered witness testimony that Fitbit’s devices recorded false positives, indicating that the user was asleep when she was, in fact, wide awake,” the court said. “Plaintiffs have also tendered expert witness evidence and testimony … to the effect that ‘Fitbit consumer wearable trackers are not currently able to accurately track hours slept, times awakened, or sleep quality.’”

According to the court, Fitbit’s other performance-related contentions—including that user error was the real source of any performance problems—were also issues of disputed fact that should be resolved by a jury, as were issues of deception and consumer reliance, which were “strongly contested” by the parties with conflicting evidence.

As a final matter, Judge Donato rejected the defendant’s claims that the plaintiffs could not prove individual or classwide damages. The class members planned to seek damages in the form of the price difference between Fitbit devices with sleep tracking and equivalent devices without, an approach the defendant characterized as a “cost-to-manufacture theory” that implied zero damages.

“Regardless of the marginal cost to Fitbit of including sleep-tracking functionality, it is a common sense inference from evidence about product pricing that Fitbit was able to charge more for devices equipped with sleep-tracking functionality than for equivalent devices without sleep-tracking functionality,” the court wrote.

Denying summary judgment for the defendant, the court set trial for April 30, 2018.

To read the order in Brickman v. Fitbit, Inc., click here.

Why it matters: Unsuccessful at the summary judgment stage, Fitbit now faces trial over the plaintiffs’ claims the company deceived consumers into paying more for devices sold with sleep-tracking functionality.