Facebook is considering charging its members $US2 ($1.98) to "highlight" important posts so they are more visible on the social networking site.

The feature is being trialled and was chanced across by a Facebook user in Whangarei, New Zealand, who initially assumed it might be a scam.

Supplied screencap of Facebook's new 'highlight' feature.

However, Facebook spokeswoman Mia Garlick confirmed it was a new "feature" it was testing.

"We're constantly testing new features across the site. This particular test is simply to gauge people's interest in this method of sharing with their friends," she said.