Sure it is possible, and who knows, maybe there are some minor talents around making their living like that. Masked as Feng Shui masters. Maybe they are not powerful enough to make it last a year, but if it works, they are sure going to get follow up contracts.
On the other hand (and something I would possibly do as a GM): Dresdenverse magic can not create energy, it can only move it. That means, if you have a year of good luck, it has to come from somewhere. Maybe some punk who would have broken into your house, and you would have easily fought him off, would brake into your neighbours house and ends up killing the poor old lady. You get a promotion, while your friend is fired. A car misses you by an inch, only to hit your fiancée.
Plus, having a spell like that on you could make you a beacon for all kinds of supernatural predators. You will be lucky enough to escape them, but once they get loose, who knows what they will do?