do providers that do CIM take business away from the ones that dont?

I have never knowingly set up a session with a girl who's not down with a bbbj/cim finale.  I certainly understand and respect those who don't, not saying they should change an iota but I can't imagine I'm the only guy who sets this parameter, otherwise why would they have that toggle in the review search engine? Fortunately, I'm in Southern California and there's way more girls who are willing to do that than I have time, energy or resources for so when ever I'm in the mood for some "strange," I've never not been able to find someone who'll do it who is also highly acceptable in other facets of the experience.  So I'm guessing the short answer to your query is "most likely," if you can get more for the same price point and quality level, seems kinda like NoBrainerVille.

9 times out of 10 I go for girls that do CIM but one of my current favs does not. In chicago finding one like that is kind of rare at least in the $300-$400 range. I don't avoid providers that don't CIM but I do prefer those that do

Yes.

...that it's possible someone won't see her if she doesn't offer CIM but that someone else Will see her because she doesn't offer it. With all that is out there to be had even though one guy won't see her another guy will so she may lose one to provider A but she offers something Provider A doesn't so she gets one from provider A.  

Like saint453, I don't necessarily avoid those that don't, but I do look for those that advertise CIM first.  And as long as they are in my price range, I will contact a CIM provider first.
I have seen and enjoyed my time with providers that do not offer CIM, in fact one of my favorites does not offer CIM. However, she is a fantastic kisser & has a great personality, which is probably why I enjoy our sessions as much as I do.

he very few times I made an exception I regretted it.

I enjoy CIM, but I have many regulars who do not do it because they have their own unique attributes that delight me as much or more.

I suppose all things being equal, it would cause a gal's business to lag; but if she can replace it with other charms, it should not affect her.

Then there are gals who don't care for a ton of business anyways.

I recall one gal who did an excellent BBBJ and knew precisely when to pull away and use her hands.  I was always more than satisfied with her technique.  In some ways that technique was superior to other gals' CIM.

Only look for providers that offer at least cim. Love oral and keeping the connection with the girl until orgasm is done makes for a better experience for me.

Just like Greek providers take business from those that don't offer it. But look at it this way, a lady that does not offer CIM, is not losing out if the guy goes elsewhere. He is not in her demographic and she not in his.

I don't do any uncovered services and haven't found my income to  
Lessen from my friend who is GFE. While there is definitely
a wide majority that will only see a girl who provides swimmers in the mouth 😄
I think you all forget there is a huge market of clients that prefer or rather
do not care. Also some cities are more friendly towards covered activities.
I find New York, Virginia, Baltimore and the lovely men of Nashville to be very  
Comfty with covered services.

My current Provider not only does this she does it with WS too. Total cost around $150.00. So I'm pretty Happy.

I prefer PIV for my orgasms.  But covered BJ's might be a deal breaker for me, unless she's hot in ways that really appeal to my other preferences.  I like BBBJ as foreplay to intercourse

I mean, there's some guys (myself included) who won't book a CBJ / no CIM girl.  On the flip side, I don't think there are many guys who INSIST a BJ has to be covered (though there may be some that prefer that, for safety concerns).