Scholarly publications can supply fellow scientists with new insights into the subject, provide information that can be used in further research and contribute to scholarly debate. Also, by publishing (especially in a reputable journal), you contribute to the increase of your research institution's prestige.
Of course, what is most important is how publishing benefits you:
- It forces you to apply structure and logic to your research.
- While revising and rewriting, you might stumble upon holes or issues that need to be clarified in your research.
- You receive free feedback and constructive comments or critique and suggestions from colleagues.
- You get experience in writing and publishing.
- You establish or increase your reputation as a scholar.
This is not to say that you can just start publishing away. The process of writing, rewriting and publishing takes a great amount of time. You must also take into account lots of criticism and rejection. Especially if you are working on earning your PhD, keep in mind that your publication is an addition to writing your dissertation, not a replacement of it.