I have been blessed with the fact that since I was 15 years old I've always had a job of some sort, and once I entered the 'business world' at the age of 22, I have never been without gainful employment ...

A lot of the talk on this thread has been about LOCATION, and it is true that if you are in an economically depressed area (aren't we all ?!?), no matter how talented you are, jobs are hard to come by ... and as the economy declines, the 'extras' - music, art, sports - suffer first ...
Obviously, it is very beneficial to be in a place that supports your type of work, and as has been said, Donny is in one of the more lucrative areas for the entertainment he provides and the audience that appreciates it ...
BUT, that being said, I am sure that there are other OMB entertainers in the same geographic are who are not working anywhere near as much as Donny, if at all ...
I'm not here to do any 'back-slapping' (wouldn't want to be accused of that ! ), but from what I know about Donny's history, like some others here, he has cultivated his customer base over several years of effort, and no doubt at times when the ROI wasn't so great ...

There are a myriad of factors that go into being successful, especially as a musician, - it is not just LOCATION, or JUST talent, or JUST marketing ... and sometimes, it is also a little to do with luck ...

But as Branch Rickey said "Luck is the residue..." you know the rest ...

Also sorry for the rambling ... I'm sitting in a hotel with nothihg to do and my KB is at home, playing by itself ...

BTW ... went back to the 'Louisiana style' restaurant next door to the hotel last night
http://blackeyedsallys.com/
and it was 'blues jam' night ... there's some really good talent out there ...
And the "shrimp po' boy" sandwich I had in honor of our 'Cajun' friends here was pretty darn good too! ...