Understand the claims process with regards to your business insurance. What must be provided to document a claim? How soon will the claim be paid out? What conditions must be met with regards to filing a claim? Since this is a key factor be sure to clearly understand how the claims process is handled by each agency under consideration.
Use caution when working with small insurance companies that do not have any history of working with businesses in your area. They may be local, state or national companies that are just getting into business insurance. Check out their licensing and their standings with consumer reports and the Better Business Bureau.