1.You are recognised for the protocols you develop and optimise, not just the results you find.
2. You can attach the protocols you use in the lab directly to your papers and view them in their full glory.
3. You don't have to waste time transcribing methods from a paper into your lab book or rewriting methods for a publication.
4.You can see the step-by-step procedures for any published research in enough detail to do it yourself.