I could start with at least 20 profitable stations in the LA market alone that don't show in the ratings or which have very low ratings (less than 0.5) but are nicely profitable. Start with KWKW, KFWB, KTNQ, KMPC, KAHZ, KALI, KALI-FM, KAZN, KBRT, KFOX, KFSH, KGBB, KAVL, KGBN, KIRN, KKLA, KLAA, KLTX, KMPC, KMRB, KOSS, KTMZ, KUTY, KYPA.
That is more than one third of all the stations licensed to the MSA. So there is definitely a place in large markets for niche formats or stations that only cover a small part of the market; in this cases covering only the San Gabriel Valley, Orange Country, the High Desert area or the San Fernando Valley.
Then start going across the nation to unrated markets like Lake City, FL or Ludington, MI, or Moberly, MO, or Lamesa, TX or Prescott, AZ, or Arecibo, PR and you will find thousands of unrated but profitable stations.