I've drifted across projects in different industries (FMCG, investment funds, ad agencies, startups of various sorts) and like I said I had a long project (over two years) for an executive search firm and got to see the ins and outs of how everything works from strategy to technology. I could be drifting to find clients in yet another vertical but I've decided to stay put for at least a few years. So to answer your question, in my particular case: I drifted, stumbled upon something by chance, and then took a conscious decision to stay.