After 2013 I made over 50 percent of my hotel visits at the request of national housecall agencies, international travel insurers, airlines, and a sprinkling of miscellaneous sources including other hotel doctors. That was fine with me.

A score of Los Angeles hotels called exclusively. That left over a hundred, all of whom had my number but who called another doctor or no doctor and sometimes me. Competition for these hotels had become so cutthroat that I was happy to leave it to others.

If you've followed this column you've learned about my excellent skills and low fees. Why would a hotel bother with anyone else? The answer is that service and price are useless marketing tools in medicine where the law of supply and demand doesn't work.

Providing a doctor produces no revenue for the hotel, and guests rarely demand one, so most general managers pay no attention. Asked for help by a guest, employees are on their own.

They may simply give out a number, but many prefer the traditional arrangement used to summon a prostitute. A bellman made a phone call. As the lady left, she stopped at the bell desk to drop off a portion of her fee.

It's illegal for a doctor to pay for a referral, but what are the options for someone yearning to break in to the glamorous world of hotel doctoring? Claiming to deliver superior medical care sounds weird. Advertising a low fee is vulgar.

Mike Oppenheim