The algorithm constantly learns based on user interactions with that particular product (for example number of times clicked).
In terms of how often the display to customers takes into these revisions, this happens on a weekly schedule so once per week you should expect to see a change of automatic product ranking.
Should you wish the learning to be applied more frequently, please get in touch with the support. If the product is given a manual score / boost from the KMC then it will remain the same unless it is adjusted or removed.