In my experience, external motivation kills internal motivation. I don’t want to be supposed to read this or that amount - I accept any pace and any pauses.
As of challenges promoting something you may not have considered, I do like the idea, though I don’t believe I’ve ever participated in those, except for some self-imposed ones and the one with Ulysses, which I’m not sure whether to qualify as a challenge.
Do you set reading goals for yourself or participate in reading challenges?
Do you set goals like reading a certain number of books in a year? Participate in reading challenges?...