If you haven’t yet heard of it, you may need to listen more closely as social media site Whisper.sh has taken off in a big way in the 18 months since its inception. It now boasts three billion page views a month.

The site allows users to post ‘secrets’ or thoughts anonymously, through the use of pictures with bold eye-catching quotes at the top, in a similar way to internet ‘memes’ – which are described as units for carrying cultural symbols or ideas that virally spread across the internet. Users tend to use the mobile app for an average of 20 minutes a day, checking content between 8 and 10 times a day, and are aged between 17 and 28, and the majority, around 70 percent, are female.

Jeremy Liew of Lightspeed Venture Partners, the first investor in popular photo messaging application Snapchat, is excited about Whisper’s incredible growth and invested $3 million in Whisper in April this year. “Three billion page views a month is a shockingly big number for a company only 18 months old,” Liew has claimed.

Where Whisper differs from Facebook, Twitter and Pinterest, is that while these sites encourage people to post things they are proud of, like party pictures and holiday snaps, Whisper is where users go to spill the secrets they would normally only tell to a close friend. Other users can post supportive comments, and users can respond to one another. Presently, users are able to download the app free but have to pay to send messages to other users.

Do you have a secret? Shhhh….