Say you mention economic research in an online essay, social media, or your web page. You want to provide a link to that research. We want to argue that you should not link to the full text (pdf file or even publisher abstract page), but rather to the abstract page on a RePEc service such as EconPapers or IDEAS. Here is why.
RePEc URLs are stable. Publishers may reorganize their website or change URLs. In some cases the URL you see is personalized and invalid for other users. But RePEc URLs almost never change, and in the very rare cases where they do, a redirection is present. Thus, you do not need to verify that the link is still valid in the future.
RePEc offers alternative versions. Say you link to a journal article that is behind a paywall that your readers cannot pass. Often RePEc proposes alternative versions such as working papers that may not be the final version, but at least your readers have something to use. Or if you link to a working paper, RePEc will offer a link to the corresponding journal article once it is published.
RePEc offers context. A RePEc abstract page offer additional links to the author profiles, cited works, works citing that research (with a count to show impact), and more. While some publishers also offer such context, it is limited to their own publications. RePEc encompasses all of economics.