Dear Nastaran Khakestary, I think that the evaluation of articles is a complicated process and I think the factor of free reading or not plays an important role in the evaluation.
A product is something that it produced, normally in a commercial environment. In the past products were almost always physical objects, but now they can be notional (eg a television programme, a business strategy).
An article is an object, usually a physical object.
When you refer to it as a product you are implicitly mentioning the fact that it is produced and (probably) sold. When you call it an article, you are not doing this
My question was about "article-to-product conversion". I never met this term and could not find anything about it on the Internet. Could you please explain it and give examples on how an article can be converted into a product? In the International Earth Rotation and Reference Systems Services (https://www.iers.org) we have products. These are freely available datasets. We publish also scientific articles. Both are based on the same scientific ideas, scientific measurements etc., but our articles cannot be converted into products. They may just describe the products or methods to improve the products. Of course, fundamental and applied science may finally lead to producing something, but I cannot imagine how an article itself can become a product and how this can be used to evaluate the article.
Perhaps we speak about different things. The term article is used for scientific publications (also called papers). These can have citations. There are also articles in grammar and in law with quiet another meaning. When you speak about an article as a physical object, this seems to be not the same as a published scientific article. A physical object cannot have citations.