Then she turns off her work phone! I've phoned girls who haven't been actively advertising and arranged something.
Me too. Girls I have seen before, I have the number for, and I know, or am reasonably sure, that they won't have a issue with me calling.
I wouldn't, however, hand the number out to someone else, particulary not to a total stranger. That's just basic respect for another persons decisions about where and when to pass out their number, about how they choose to run their business. I don't know why she has stopped advertising, and it is not my place to second guess that decision. I would behave this way with respect to anyone in any business or in none.
That's why I illustrated my point by asking Sandman why he didn't post his number. Care to post yours? Or would you prefer to retain control over how, where and when you share it?
As for not giving information out just because they are a newbie, what's all that about 
I don't know, I didn't say it.
If I had to guess it would have something to do with being less certain of the motivations of someone who pops up and asks for a specific girls's currently unadvertised contact details, versus a long term cunt-hound who has been contributing here for the honourable purposes of seeking twat for cash for a wee while.
But as I say, I didn't say it.