The featured bocks usually have different results. It's considered that, higher on the page, better is the result ( e.g. "Weekly Featured). Usually one novel stays about 48h up to one week. It depends if the novels is being successful in grabbing readers, it seems (so they renovate its feature a bit more).
But... By the end of 2019 an author could expect at least 400 collections from 2 days of features. Some bragged they could reach 4k+ of collections in a single week of a Weekly Feature. It's no longer true, due to the abuse of features and banners, the saturation of new novels, and other external factors.
Readers used to think featured novels were curated and high quality, but it became obvious they aren't, so it doesn't have the same impact as before.
As far as what I personally got, my best result was around 800 collections (2019). And my worst, recently, 12. 😂