I only contact references via email, and that can anywhere from a few hours to a few days to hear back. Generally always longer than 10 mins.  

On the other hand, that's one reason P411 is a great tool. Your references are all right there, and as the ladies have to personally okay you, it's usually more trustworthy. As opposed to just giving names and us hoping you really did see the ladies. So depending on who your refs on P411 are, and how recent, she may have looked it up, and decided you're fine. I like to doublecheck sometime personally, just depends on the situation.  

Some ladies don't actually check references if the names they are given are well known. Always smart to check!

I find this a very typical time line with girls from P 411 with "available now" ads.

9:00 AM I send a PM (not an appointment request) asking about availability for "today" along with an invitation to check out my profile and okays before getting back to me.

9:05 I get a message from P 411 that my profile has been viewed.

9:15 AM I get a PM from the provider asking "what time would you like to see me?"

!0:30 AM I am balls deep inside of her. lol

The more okays you have, and the more current your okays the more likely it is to be this easy. A lot of P 411 providers upon seeing a few dozen okays with at least a few of them being within the last month or two AND from a name she recognizes, will immediately feel at ease and be willing to schedule a session.

Numbers and emails by heart  so in most cases i can give a reference almost instantly