Beyond SSRN, abstracts are important to catch a potential reader's attention and motivate the reader to continue reading your article.
Eugene Volokh, a professor at UCLA School of Law and author of Academic Legal Writing, devotes a section of his book to writing abstracts. From the draft section of the book:
"The abstract is an advertisement for your article. True, you don’t want money from your “customers” (the audience) — you want their time and attention. But their attention is scarce, and lots of authors are competing for it. You want readers to “buy” your article in one of two ways:
- by reading the article (or at least the Introduction) right away, or
- by remembering it (even if just vaguely) for the future, so that when the underlying issues becomes important to them, they can find and read the article then."
"You need to quickly show them this value. You need to clearly and tersely tell the reader (1) what problem the article is trying to solve, and (2) what valuable original observations the article offers. Naturally, the abstract can’t go into much detail. But it has to at least give the reader a general idea of what the article contributes."
Volokh offers sample abstracts and discusses the pros and cons of each. Keeping these concepts in mind, it is also important to try to use pertinent keywords in your abstract to aid in discoverability.
For more information on writing abstracts, see Colorado State University's guide to writing abstracts.