That's completely inapplicable to permanent positions. The current company of a prolific employee is not gonna lay him off and send him to a competing company.

That's completely inapplicable to permanent positions. The current company of a prolific employee is not gonna lay him off and send him to a competing company. It can make sense for consultants, doing short gigs here and there. People can refer you elsewhere when the current work is completed, they ain't gonna keep you anyway.