Several ad sites have an available now option. From connecting with people I have found definitions very of what that means. For some they are available and ready to meet or within an hour or 2. Others it means they have an opening later that night. Some said it means they are available to verify for a meeting days in the future.  Some were unaware fitness even on for them.  

Come now, before I book someone else, but be prepared to wait, cuz my last customer is still here.

I think there may be some using available now in a manner inconsistent with its intended purpose.   Personally I would assume it to be literal, as in the provider is fully prepared to meet at that particular time. However as you have noted, this is not always the case.  

If you're looking to meet someone soon your best bet is simply to reach out and ask.

Nah.

means whatever the provider using this vague term means.  In the old days of CityVibe, it meant that she still had same-day appointments available, but they were subject to other customers booking before you do.  It could mean in an hour, or it could mean in 8 hours, depending on how many respondents she had to the "available now" flag on her ad who booked before you did.

Some sites I look at when traveling have that information listed but they are also sites that allow direct messaging with the escort via the site so you can schedule you appointment from the ad site. If that is what you're looking at, then I would take that to mean the provider is logged onto the site and has not been book via the site as of that time.

As mentioned, the term is used broadly, to mean many things.  I would expect it to mean, "I am available today, if the time you desired does not conflict with any existing bookings and and assuming that you had previously passed verification."  In other words, it can only be taken literally by previous clients.

There is actually significant consensus about what GFE and PSE means. There are plenty of sites that define terms/acronyms and the definition is consistent, if not concrete. GFE means kissing with tongue, also known as DFK, is included. PSE means anal, COF/CIM and other more extreme acts are on the menu. The only people who disagree with this are providers that want to charge GFE/PSE prices without providing GFE/PSE services. They are lying. I will never accept the premise that these words are ill-defined and vary from person to person. Nobody said that shit 5 or 6 years ago. This is why reviews are essential.  
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VIP on the other hand is absolutely meaningless and can mean almost anything based on the provider.

I am available now to take advanced booking requests. I am never "available now" because it takes time to screen & prepare for potential new friends. The majority of all my bookings are made way in ahead of time. Proper preparation prevents poor planning.​​ Expedited service same day appointments add $200 rush fee.

Means we will be available with 2 hours notice.

Thats how interpret it.

So if someone books the girl who's available, who changes the status of her availability and how fast is the turnaround?

It is a way for the provider to bump up the ad.  It does not necessarily have anything  to do with availability

So my ad gets seen, &  possibly same day appointment or next day. Even if I was fully dressed and ready to go most men thinks it means in 5 mins which is kind of impossible even if you’re in the same area.  

Available for Booking

When I post available now it means I’m available in general for booking. There is no other way to repost the ads. You just click a bottom every few hours so you stay visible to potential clients and the ad stays active and visible. If someone has already booked me for that day I’m still available just not at the time of my already booked appointment. That’s why it’s best to just check the providers website to see their booking procedures. It typically requires at least a 24 hr notice if it’s an upscale provider. Hope that helps