Research Opportunities: SoTL is research; quantifiable and rigorous research. More and more departments are counting SoTL publications toward decisions about tenure and promotion, though this is not yet universal.
Effective Teaching: By its very nature, SoTL directly impacts how effective your teaching is in terms of student learning. Engaging in SoTL will help you become a more effective teacher, as you become increasingly aware of your classroom practices and make strides toward systemic change. You will learn to focus your attention on continual assessments of your teaching practices.
Tenure & Promotion: Teaching effectively is one thing, but proving your effectiveness is quite another. SoTL makes it easy to demonstrate your practices in the classroom, and highlights your active interest in improving your teaching. Outcomes from SoTL research make natural components of teaching portfolios, which are often used in tenure & promotion decisions.
Renewal: Looking for new ways to examine or enhance student learning can help reinspire you as a teacher. For further inspiration, read: Teaching With Fire by S. Intrator and M. Scriber, 2003.