Even though you have had the seventh interview in a week for seven similar roles, it's essential to treat each one as an individual event, and to prepare accordingly.
Research the company: The corporate website goes without saying, but look at their competitors too. How do they differentiate themselves?
Research the interviewer: What is their background? LinkedIn is a favorite.
Research the job: This is vital. How can you effectively interview if you don't fully understand the role?
Most importantly, know what makes YOU the IDEAL person for this job!