When a user slowly becomes immune to its actions and attractions, a group of researchers at Princeton University predict that 80% of Facebook's users will have abandoned the site by 2017.

John Cannarella and Joshua Spechler based their research on the number of times 'Facebook' was entered into Google. Google Trends' chart show that the searches peaked in late 2012 but have begun to trail off since.

"Ideas, like diseases, have been shown to spread infectiously between people before eventually dying out, and have been successfully described with epidemiological models,"

the authors claim in a paper entitled 'Epidemiological modelling of online social network dynamics'.

When researching, Spechler and Cannarella used the SIR (susceptible, infected, recovered) model of disease, which creates equations to map the spread and recovery of epidemics.

Also, as part of the paper, they tested various equations against the lifespan of Myspace. Myspace was founded in 2003 and reached its peak in 2007 with 300 million registered users, before falling out of use by 2011. With that as a base, they then adapted their findings to Facebook.

The 870 million people using Facebook via their smartphones each month could explain the drop in Google searches – those looking to log on are no longer doing so by typing the word into Google. But Facebook's CFO David Ebersman admitted on an earnings call with analysts that during the previous three months:

"We did see a decrease in daily users, specifically among younger teens."

Perhaps without innovation, Facebook's days are numbered.