From my observations, the main, or possibly even sole criterion seems to be how many likes you've had over a fairly short period of time (maybe a few days?). Being in a smaller, less popular genre (action) it's easy for me to track my performance compared to similar comics and to see the relationship between surges in likes and jumping up the rankings in my category.
Because it only tracks based on recent likes, not cumulative likes, any comic that gets a surge of them can rocket up the rankings at any time, even if it's been on hiatus. Frequent updates mean you'll be more consistently getting likes and appear more consistently in the higher spots, which means you're more visible, which means more bookmarks, which means more likes, so consistent updates do help, but in a roundabout way.
In other words, if you want to do somebody a solid, like all their pages in a short period of time. I've had days where a couple of new readers liked all my pages and my comic leapt really far up the genre rankings.