Perfectly reasonable question! :-) I can only speak from the strategy consultancy perspective, but the flippant answer is: pretty much whatever they want to do! More specifically, and I'll try to get this in approximate decreasing order, I've seen lots of people move into: corporate strategy roles (perhaps unsurprisingly), banking, corporate line/exec roles, private equity, fund management, and their own entrepreneurial ventures, plus a smattering of charities/NGOs, public sector management, civil service, and teaching. I would strongly agree that consultancy can be an excellent training for future careers, but I'd never advise anyone to do it for that reason alone, unless they also thought they would enjoy the experience itself. Life's too short (IMO).