Questions over whether Facebook will one day introduce an ad-free subscription version have been around for years. Now, it seems the social network could be moving a little closer to this option, as it's reportedly been conducting market research to gauge the public's interest.

Facebook has examined adding a paid-for version of the platform in the past, but in the wake of the Cambridge Analytica scandal and other privacy controversies, the company is reportedly stepping up its plans.

According to Bloomberg, Facebook has been investigating whether paying a monthly or yearly fee to avoid ads would encourage more people to join the social network. Those familiar with the matter did stress that nothing is set in stone, and the plans might not move forward.

Facebook's executives haven't ruled out the possibility of subscriptions. "We certainly thought about lots of other forms of monetization including subscriptions, and we'll always continue to consider everything," said Chief Operating Officer Sheryl Sandberg, during the company's first-quarter earnings call.

Despite its recent controversies, Facebook's revenue was up 49 percent YoY in Q1 2018 to $11.97 billion. Ad revenue made up $11.8 billion of that, and 91 percent was from mobile.

Facebook's ad targeting practices is one of the reasons why people have been leaving the site recently, but it's unclear how many would be willing to pay a subscription fee to avoid advertisements. It's likely that people who hate ads would prefer not use Facebook at all. But one thing's for certain: you'll never be forced to pay for the service. As Mark Zuckerberg said during his congressional testimony, "There will always be a version of Facebook that is free.''