Around 635,000 people bought an NFT last month, for US$427 on average, according to market tracker CryptoSlam, down from about 948,000 for US$659 in January.

The metaverse is theoretically the future of the internet, a 3D virtual world where people will be able to interact using sensors, lenses and other gadgets.

The deal underscores how valuable the Meta name has become for the technology giant, which is betting that its focus on the metaverse will pay off handsomely in the coming years.

Horizon Worlds is far from a fully realised metaverse, a future internet where online experiences like chatting to a friend would eventually feel face-to-face thanks to virtual reality headsets.

According to crypto data site Dapp, land worth more than US$100 million has sold in the past week across the four largest metaverse sites, The Sandbox, Decentraland, CryptoVoxels, and Somnium Space.

Decentraland is an online environment - also called a 'metaverse' - where users can buy land, visit buildings, walk around and meet people as avatars.

San Francisco-based Unity Software says the US$1.6 billion acquisition would 'shape the future of the metaverse', an immersive 3D version of the internet tipped to transform workplaces and online interactions.

The 'metaverse' refers to a shared online world in which multiple users can hang out, spend money, consume media and potentially even work.