To be clear, this is not a suggestion that Facebook is trying to find a way to get everyone to pay to log in. As Zuckerberg stated in his congressional testimony in April, and as Bloomberg notes, there will always be a free version of the site. A paid version would simply be available for anyone who'd prefer an ad-free experience. It also bears repeating that none of this is confirmed to be happening yet, and the company could very well abandon any plans it might be working on. Facebook has considered adding a similar subscription fee option in the past, but Bloomberg argues that the intense scrutiny lately may have shifted thinking on the whole idea to a point where it's closer to becoming a reality.
It's tough to imagine what Facebook without ads would even be like. Unless you joined the site in its most nascent stages (and when it was still "thefacebook.com"), you probably can't even fathom what it would be like to be on the site or mobile app without being inundated with advertising in some form or another that seems to follow you all over the damn internet.