Marketing positions cover a variety of roles, ranging from technical market analysis to creative storytelling. If interviewing for an analytical role, expect to answer statistical questions about market trends and patterns. If interviewing for a non-technical role, focus on highlighting your strong written and oral communication skills as well as your experience running compelling campaigns.
I was given business with 2 of the 11 in-person interviews. These were based on a real life problem that they were struggling with (can't remember the details at this point). However, I do believe that one of the interviews "went off script" and didn't ask the standard business case that he was supposed to ask.
Overall, a fair process. I appreciated meeting lots of people, but I can see how that might be a barrier or upsetting for other types of candidates. It was a bit odd that I wasn't entirely clear which job I was applying for.