I'd recommend signing up at
Brring. They pay you everytime someone calls the number and its free.
I started giving my Brring number out online for surveys etc. (basically anything I fill out online) about a month ago and already have earned $15!
As for the "Private" number on Brring I simply got an invite to
Grand Central, set the "Private" number to the one given to me for Grand Central and put Grand Central on Do Not Disturb.