The way the popularity filter is calculated is based on the number of times a particular item was clicked on across keyword searches and the position that the item displayed on the page at the time it was clicked on. At anytime we only look at the data for the last 30 days.
We recommend that you keep the value between 0 and 1 to ensure that the search result's relevancy still has a strong impact on the order the items are displayed in. This helps safeguard that an item does not appear on top because it is popular, even though it is not necessarily the most relevant search term. In essence, the score should always have more weight on the order than on the popularity for search requests.
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