It depends on the "ratio economy" of the tracker.

Some are very hard: Bibliotik offers very few opportunities to build ratio. Very few people download any given random book, and there is no source of free credit. The economy is very feudal with no real inflation.

Some are easy: the ratio requirement on btn is nominal, and the real requirement is that you seed single shows for at least a day and seasons for a week. The system especially penalizes 'Hit and Run' downloads (i.e., not seeding for the required amount of time) rather than overall ratio. This acknowledges the ephemeral interest of a given TV show, and that each new show release is effectively a 'holiday' event.