I agree with Jason on Ortho-k (also known as CRT). I dabbled in it back in 2003. Had to buy a fitting set for $3,000 and I fit 3 'patients'-- two employees and my daughter. Ranging from - 1.00 sph to -4.00 sph. Actually ALL 3 were 20/20 within two days!
Awesome. I was very impressed (must use a corneal topographer). But even for free, two chose to go back to soft lenses and one opted for Lasik. Upon questioning, they stated if they are going to have to wear contact lenses, they might as well wear them during the day (as opposed to every night as in Ortho-K). (For those that don't know, they are basically like "braces" for the eyes--they flatten the cornea temporarily but return to normal if not worn at least every other night--usally every night--for ever.)
The 'killing' factor is usually the fitting fee and cost of lenses-- around $1,500. Most candidates will just opt for the one time (slightly higher) fee for Lasik.
The biggest market I suppose would be kids too young for refractive surgery. But with daily disposible soft lenses, I didn't get many kids parents that were interested in Ortho-K. Ultimately I sent the fitting set back for a refund before my 90 trail period ended.
So in summary: Ortho-K works. But most prefer other alternatives. And, once again, as with Vision Therapy and Low Vision, it's not that mosty ODs haven't tried to make money doing it. They have. Most probably have at some point or another. It's just that it's very difficult to do when insurance doesn't pay for any of them.