For the second time this year is slashing, Facebook is temporarily dropping the price of its Oculus Rift virtual reality headset and Touch motion controllers bundle, this time pricing the entire package at $399 — matching Sony’s PlayStation VR unit. The discount will be available for the next six weeks as part of Oculus’ “Summer of Rift” event, which also includes up to 60% discounts on more than 30 VR titles available for Oculus Rift and Samsung Gear VR.

Aside from quality content, getting the cost down is key to the long term success of virtual reality and Oculus is well aware of that, but the recent price drops suggest that sales have been sluggish.

According to Jason Rubin, head of content at Oculus, the average number of Rift headsets sold each week went up after the first price cut and now that are temporarily lowering the price again to capitalize on a dramatic increase of content in recent month. The company says there are more than 700 apps and games for Oculus today, up from roughly 400 in March.

“From AAA games like Batman: Arkham VR, Star Trek: Bridge Crew, Robo Recall, and Wilson’s Heart to interactive films, immersive experiences, and beyond, there’s a ton to explore in VR. Thanks to multiplayer games like Echo Arena and social apps like Facebook Spaces, you can compete or connect with virtually anyone, anywhere.”

Oculus hasn't disclosed sales for the Rift but research firm IDC estimates the device has sold about 520,000 units world-wide to date, compared with 770,000 of HTC's Vive headsets and 1.6 million PlayStation VR headsets.