Your points are well taken.  However, the phone number thing is not always a caution sign.  Many people, both in and out of the hobby, do not change their cell numbers if they move to another location.  That avoids having to tell all their contacts they have a new number.

You can look for providers ANYWHERE, but if you don't find reviews SOMEWHERE, avoid.  Too much chance for many of the pitfalls of the hobby to land right on your little head.  The only exception to that rule for me is if a personal friend that I trust vouches for the provider.

Swim

It takes time to properly research a provider by stage name, phone, email address.  It is helpful if a lady tells you where she has reviews.  I've even asked...  sometimes a lady might have reviews under a different name.  (One lady, returning to the business after a few years away due to a relationship.)  
It does take time but it's the best way to prevent disappointment.
skb

I've been browsing over the backpages escort ads.  The ads certainly look rather fake and I'm wondering if anything on there isn't a scam.

Examples of what looks suspicious;

1) Weird subjects, like "♥°o°• EVERY•°o°• MAN'S •°o°• FANTASY •°♥* SoMeTHiNg YoU MuST ExXxPeRieNCe!!! - 2"
2) Ads with overly-professional looking pictures
3) Any other city which would have a disproportionate number of ads. (in Michigan, there's a ton of ads for Southfield, MI, for example, a city known to use the Internet for entrapment)
4) The out-of-town phone numbers.

So, my question is -- what do you look for on a site like backpages to determine if a SP is real or a scam?  What sorts of scams are out there to worry about?

I had a similar question in a post a few weeks ago.  More experienced posters may want to add to this, but here are two points:
1)  In general there are a high amount of Backpage ads where, at a minium, the pix aren't real.  So if you see an ad with a drop-dead gorgeous girl in it who's asking only $150 for an hour, you can be pretty sure you won't be meeting the gal in the picture.  Maybe her Mom.
2)  Despite the above, many reputable, well-reviewed girls post ads on Backpage in areas where they're touring.  But if they do they usually have a link to their web site and/or TER reviews.  Those are the ones worth looking into but you won't find bargain prices.  In the hobby or anywhere else, you get what you pay for.

For an example of a scam, see my post below

reviews.  No reviews = no date.

I screen really throughly. I do more than just read her reviews. I find about 20% of the ads are on the up and up though some of them may only offer limited services (no BBBJ, no DFK, or FBSM/hand-job only types), about 40% can't be screened enough to know anything real about them, around 40% are ether bait and switch, upsellers, robbers and/or some other kind of scam, and around 1% are LE stings. Screen well and you can find a diamond in the rough, don't screen and you will likely get burned.

Reviews are the easiest way to screen, but there are other ways like back-channeling, provider referrals and the like can get you the information you need to stay safe. Even if you are not shopping backpage screen every provider you see. There are cons everywhere even here. Everyone in this hobby should screen everyone else in this hobby.

Very good advice.  But for me, that seems like too much damn work based on a 20% "up and up" success rate.  To each his own, but I'll stick with well reviewed providers.  I don't want anything to do with the other 80% you describe.

I was robbed once; it will never happen again. I have found LE on other sites as well as bait and switch, upsellers, and the like. I found through my screening a lady hear on TER that likely, although I can't prove it, pressers her clients to post false positive reviews or not review at all with fear of outing or blacklisting them. Screen everyone. As I only have hear say on this lady, I will not spread what I have heard, so no PMs please.

Please, also note that some of the 40% or so are likely legit I just can't prove it. I don't trust reviews as my only source of screening. I screen more than most hobbyists. My wife thinks I am paranoid. Only 30% of those who advertise here get past my screening. Not much better than Backpage.

"My wife thinks I am paranoid."

Wait, what?

I believe he has said before that his wife is a provider.

lollllll

My wife more than knows I hobby she actually encourages it. She is an escort. She feels that by me playing it brings balance to our marriage. And she thinks I am paranoid in my screening. I just don't trust one source of screening information. Every time I have it hasn't gone so well for me. I spend hours screening each lady I see before contacting her.

Hey Duffos, If you can't say something nice once in a while, you might want to . . . .  Nah, can't say it since this is the Newbie Board and we are supposed to be nice to everyone so we don't scare off the new players.  At least learn to use EOM.