Aerial photography, which is what I happen to have some experience with, have mainly been on a "side-show" basis. People call me up and ask if can take pic's of their houses/businesses.
Have even done the odd air-to-air job. Which have been really cool. Haven't been flying myself on those occasions though!
Air-taxi is, I suppose, just a matter of being at the right place at the right time. Hasn't happened to me yet. Although I have done a decent amount of freight flying for my current employer.