Facebook came under fire recently for experimenting with 700,000 of its users' moods by altering their newsfeeds, but an interesting counter-experiment that makes the site the subject of investigation is taking the Internet by storm.

"99 Days of Freedom" sees users stay away from Facebook for 99 consecutive days, filling in a "happiness survey" at 33, 66 and 99 days to see if taking a breather from the site affects their mood.

Users set their profile picture to a "time-off" image provided on the 99 Days of Freedom website and receive their own personalized, 99-day countdown clock.

The concept was dreamed up by Dutch-based creative agency Just and began as an office joke.

"Like a lot of Facebook users, many of us were bothered by reports of secret mood experiments," says Just's Art Director, Merijn Straathof.

"As we discussed it internally, we noted an interesting tendency: To a person, everyone had at least a 'complicated' relationship with Facebook.

"Whether it was being tagged in unflattering photos, getting into arguments with other users or simply regretting time lost through excessive use, there was a surprising degree of negative sentiment.
"Then someone joked, 'I guess that the real question is, 'How do you feel when you don't use Facebook?"

According to Facebook, its 1.2 billion users spend an average of 17 minutes per day on the site, which amounts to more than 28 hours over three months.

However, Straathof stresses that the initiative is neither an anti-Facebook protest nor an attempt to harm the web's most popular site.

"Facebook is an incredible platform, we're all fiercely loyal users and we believe that there's a lot to love about the service," he says.

To sign up to 99 Days of Freedom visit: http://99daysoffreedom.com/