I saw this provider online who claims to be "independent" but the number that's included in the ad is the same one that is used in multiple ads for many different women. They make no claims of belonging to any kind of Agency so it almost seems like its false advertising at the very least, or possibly a bait & switch at the most. Since I am a relative novice at this, I would like to defer to the experts for advice. Should I call this person? Is outcall preferable in instances like this or should I go with someone else entirely?

Okay thanks for your help. I think I will get a list of questions together but I will try to be as polite and non explicit as possible. I'd rather not throw caution into the wind, but I'm not in a financial position to afford some of the top shelf providers who are reviewed here either. At the very least I'll try to look up more info on this provider and see if its worth pursuing.

As impposter said, it is possibly a booker or assistant's phone number.

Okay. but just to clarify, from what I have seen, this phone number seems to be shared among 3-4 different women so it's not like a huge operation with an agency running hundreds of providers all over the city of Chicago. At first I thought it may be operated out of a hotel suite that's being rented by a bunch of young professional women looking to make an extra buck, but I've been doing some digging and these women haven't been reviewed either on here or anywhere else.
If you want the number it's (312)785-0042 and you can run a google search on that. I'm not even sure if these girls are using fake pics so an extra set of eyes would be extremely helpful.

Searching the phone mumbervyou posted, I find nothing. However a number very slightly different produced several Provider ads. Is your phone number a typo?

Sorry it looks like I can't post the ad. the correct number is (312)785-0422 and the provider's name is "Shannon"

These ads scream fake, TGTBT.

I didn't see Shannon, but the women I did find in Chicago associated with that number look TGTBT to me.  

is definitely too good to be true.

I didn't go looking for her, per se. He said there were others so I just went after that phone number and stopped once I saw all I needed to see. Elizabeth is as well. LoL.

If it's TGTBT it probably is.   There are sites to image search.  If the mages pop on ads all over, they are stolen.  Even low budget providers get reviewed on TER pretty quickly.  

NOT ganging up at all.  Just pointing out the lessons to be learned...  not just for the OP but all the otherswho seek to learn here.  
The points are TGTBT probably IS
Image search.

So I came across another ad that had the "It's me or its free" line that I have seen almost everywhere. I've always been curious about statements like that. On the surface, it seems like a pretty bold claim. A provider is basically staking their entire reputation on their word, and simultaneously is hedging their bets that now customers will have to flock to them, because who in their right mind would say such a thing and lie about it? But is that really all it is? One of the biggest bald faced lies in the industry that is just for driving up turnout? is it an LE tactic?

Her ad said "'100% me or it's free" so I booked an appointment and when I showed up it was not the girl in the photos, so I called her out on it, and she gave me a free session..." LOL. That is obviously not going to happen.