It looks like it. Obviously my observation could be quite limited. But here is the background, in the good old days, Apple ranks app mostly by the download number in a given amount of time, and the ratings/reviews. So basically the popular the app, the higher the rank. This process could reinforce itself. Apple realized this approach probably has its limitation, one example being a fairly popular app Facebook (by usage) is not ranked the 1st. So Apple changed its algorithm a bit, it not only ranks by the download number, it also monitors the usage. By “usage” I assume Apple measures mostly by network activity, my reasoning being if an app just does its thing locally, Apple has no way to know it.
Also keep in mind the rating and reviews also play a role in the ranking, my understanding is if all things equal, higher rating or favorable reviews will push the rank higher.
More recently, it seems Apple started to give usage more weight. This is just from my own observation, I have 2 little apps, both are standalone (no network features), and one does fairly well last few month, until recent, it totally went down cliff. I did not know why until I did keyword search, in the past, it ranked 2 or 3, not it fell out of top 25. I tried to rescue such as free download for a limited time. After the free period, download number drops back, and this thing fell out top 25 again 🙁
I think from product lifecycle management (PLM) point of view, this app thing is not as good as traditional software revenue model 🙂