Can someone explain how to use this feature and what the benefit is?
Freeleech lets you download without it counting against your ratio. It also has a bonus of counting your uploaded data towards your ratio, and it helps your ratio the longer you keep sharing and others keep getting it from you.
You don't have to do anything special to use it, just download and share as normal. Staff will recycle torrents to the front page to give members a chance to check it out and download it, and often will make some freeleech.
You and any of us members can also make certain torrents to be freeleech when we have enough seed points (but it will not go to the front page). If a torrent you want does not have many seeders and leechers, using freeleech and Requesting Reseed at the same time can make it more active.
It's both a tool and a gift worth checking out to enhance your experience here.
Freeleech has 1 important bit, that most people forget.
All freelech has a set time limit.
As an example; if I set a torrent to freeleech for 94 hours, it stops being freelech when that time is over. It doesn't matter when you get the torrent file, if you have not finished downloading the video when the time is up, it will start counting against you from that point.
Any part of the video that you got while it's freeleech is "free" while any remaining part will count against you.