Database - Currently still irregular Updates
The product detector is a huge and complex database of millions of products - ie. it is not a live search of the product on Amazon.
The lower the product's salesrank, the less often (up to bi-yearly) it's data will be updated. There may therefore be various diffrences to the data in the product detector and the live data on Amazon.
Advantage: See development of relevant KPIs & Source of Inspiration
The Product Detector not being 100% up to date at least offers the advantage of being able to see the products' developments that have since taken place by, for example, comparing various figures to the results in the Niche Analyzer, which is live.
Please note: the Product Detector is meant to serve as a pool for inspiration as to what kind of products are selling well on Amazon or online in general, while further analysis should be done with the Niche Analyzer, Spy or camelcamelcamel.com.
Limitation: Only "Well Selling" Products in Database
Furthermore, the product detector is not a full list of all products available on amazon, but a database showing only well running products. For this list, the detector will only register products with a good* salesrank in the main or first under-categories. This should offer inspiration as to what types of products can really provide solid demand.
*good is relative to each product category, as rank x can stand for 10 daily sales in category 1 and 50 sales in category 2.