It's great that WATD is live and local 24/7, but as far as I know, the DJ's on after 10 PM are not paid. It becomes a brokered and/or volunteer station from 10 PM to 5 AM.
Wide World Of Blues is brokered. They buy the time and get sponsors. I don't think that the late-night oldies and Doowop shows after the Blues show buy their graveyard shift airtime, but those DJ's are also not paid. Some of them do have some local sponsorships and spots, perhaps they get to keep some (or maybe all) of the revenue, I don't know.
It's really great that they have a visually-impaired DJ a few overnights a week (Ted McCaw) doing a deep '50s oldies and Doowop show out of his own customized studio at his home, using an audio link to the WATD studios! (It's a mono link, but most of the music he plays was never originally recorded in stereo anyway). What other commercial station anywhere would allow a blind DJ to live out his dream nowadays?
I do love listening to all those oldies, blues, and various other specialty shows on WATD. The hosts are all very dedicated, extremely knowledgeable about their genres, and passionate about what they're doing.