I think the key is to focus on fringe/niche questions. Of course this wont make you a lot of karma, since relatively few people search for fringe things. But at

I think the key is to focus on fringe/niche questions. Of course this wont make you a lot of karma, since relatively few people search for fringe things. But at Internet scale, that can still be a considerable amount of people reached over time. And writing good written answers is usually good for ones learning as well.