Sure he can make money. Will he? Remains to be seen. Michael isn't on just one station - there are a few he's airing on. Some businesses might find that a worthy investment. Hopefully, he has a few sales folks doing the pitching besides himself. If he has other revenue sources that can take care of his personal life (rent, food, etc.) then he doesn't have to make money - he just has to scratch up enough sponsors to pay for the brokered time. One school of thought is that he had put away some money and is working off that to fund the radio product until he has a few sponsors to pay the bills, and not taking a salary himself.
I can't/don't listen to Michael (due to location/time), but I personally would like to see him succeed, just so he could stick his middle finger in the eye of those who doubt the abilities of local/regional AM radio.
As for "a high priced radio talk show host like Howie Carr" having his salary covered by advertisers - it happens every day, on every radio station (high priced talent or not). Advertisers pay to be on a station (some just on a particular show). Those revenues pay not only people like Howie (the on air talent), but producers, sales reps, managers, receptionists etc.
Marc