never seen a provider a second time. By choice or otherwise.  
If you haven't seen any provider a second time, how many different women would you say you've fucked in your career? And why?

Then there are the ones I've seen in other countries and there it's a lot less than 50%, for obvious reasons.
As for the US women, bear in mind there are lots of different reasons for not repeating and many whom I'd love to see again.  So not seeing someone a second time does not connote anything negative

I haven't seen the same ones twice, just because there are so many to choose from.  But I would gladly see them all again if I had the budget for it.

I've seen two providers with multiple occasions.

guess that makes you a qwik learner ...lol
not my experience but there have been OIAM  
dates that I've kept that way. But very few. 2 or 3

If the first session is bad I don't see her a second time. If a provider is great the first time I see her multiple times.

Mostly due to great connections with these lovely ladies and of course the perks are a bonus!

I like meeting new and revisiting wonderful providers that I have seen in the past.

No shit!  6 or 7 a month.  I wish I had your budget.Lol

So far, I've repeated with every lady that I've reviewed on TER several times, but there are far more providers that I've seen who I've never reviewed.  I also have a couple of favorites who are UTR that I'm currently seeing.  Just taking an educated guess, I think the ratio of repeats to one time encounter is somewhere around 60:40.

I have seen 50 providers for repeats. Over the my hobby career about 90 women. Many retire and go on. I will stop seeing a provider if they have drama issues and/or late all the time.

about two thirds.  Not sure what you mean by how many I fucked in my "career."  I didn't get married until I was almost 30, so as a civvie, I would estimate about 500, then only my wife for nearly 20 years, then between 450 and 500 in nine years of hobbying after my wife's passing.

I've seen ladies 5, 6, 10+ times. Way back in the day when I picked up streetwalkers I used to repeat with the good ones. The only time I don't repeat is if it's a touring lady and she doesn't come back, or if I was not satisfied with the session.

but often that is not possible because they don't come back to my town, or I don't go back to theirs, or they retire

I rarely don't repeat. I go back because I really had a great first time and my experience has been that as we get to know each other the sessions progress and evolve.  The ladies I see are really good at changing things up from vanilla to BDSM etc.  
I guess the process of finding new ladies is not a thrill for me. I get a little overstimulated in the unknown.  
I've been really lucky with my research and choices so far

I don't hobby super-often but most of the time when I do it's with my ATF.  Sure, I try out new girls if I see something that suits my fancy, but I found what I like and stick with it.  She's gorgeous, sexy, intelligent....everything I want in a provider.  We know what the other likes and doesn't like, so it's always good.  The thrill of the chase and the anticipation of the next new thing can be fun, but I also like the certainty of a regular thing.

Most providers I have seen, I have seen only once.  There is no ONE reason.  Some I wanted to run when they opened the door, some were jerks, some were wonderful but were just visiting.  Just as the ladies say they have to kiss a lot of frogs until they find their prince, finding a really good ATF and keeping her close is a numbers game.

I've seen about 60 providers over 20 years of hobbying. For the repeats - it's usually a combination of the sex was spectacular and the girl didn't treat me like just another trick - it actually felt like we were dating and there was a connection. The kind of girl I would repeat with is one who when I ask her if she wants to get something to eat after we've fucked, she says "Yes, absolutely I'm starving!" instead of "Sorry hun, I've got another client waiting outside."