It was really fascinating to read your today's email about landing a McKinsey offer while coming from advertising. Because this is exactly what I'm going through now: I work in a top ad agency in [European city] and I'm in a middle of my preparation process for interviews in MBB.
In case you would be so kind as to give me some recommendations personally, here is my background:
I have a bachelor degree in Management from Graduate School of Business Administration - a faculty of [XXXX], one of the top universities in [writer's country]. I worked 1,5 years in audit right after the university, then understood that it wasn't exactly my dream job and moved to a position of a Strategic Planner in an ad agency - one of the top agencies in [writer's country] and globally. I came in as a Junior Strategic Planner and in 2 years became Strategic Planning Lead for the agency's biggest and most important client.
Strategic Planning in ad agency is the equivalent of marketing: we do consumer analysis, competitive analysis, define and estimate target audience, create strategies for new product launches and communication, etc. Therefore I have good analytical, qualitative and presentation skills, but quite frankly my math skills are not very strong (in fact they are terrible and that's what I'm working on now) and the overall approach in agency is not 'quantified' and structured enough (it's more of an lateral / entrepreneurial / brainstorming kind of thinking).
I would be happy to hear any suggestions in terms of approach to preparation process, books, resources, etc. you might have, providing you have a couple of minutes of spare time.
Thanks a lot in advance, hope to hear back from you.
Given your background, there are two things I would suggest:
2) Practice a lot before you know if you have an interview. For people coming out of the ad agency world, their view of business is very narrow. It is a "campaign-centric" industry. In contrast, consulting is not. So to some extent you need to unlearn some of the basic assumptions everyone in the ad world tends to have, and re-learn a different way (and then integrate your ad experience into this newer approach).
The fastest way to unlearn, learn, and integrate new skills is via my Look Over My Shoulder® program. It is the same program that the person who I wrote about in the article referenced as being very helpful. More information can be found at: www.caseinterview.com/loms
Good luck and don't forget to practice a lot.