I noticed that a number of reviews end with a plea for its readers to "treat her right." I'm really wondering about this convention -- why is it so frequently invoked? I have three theories and would like to get some feedback:

One dummy started and other dummies thought, it is good way to kiss up to the providers hoping they will get something special next time.

Indifferently, brusquely, uncivilly, unmanneredly, disapprovingly, reprehensibly, badly, harshly, cruelly, shamefully, wrongly, wickedly ...

to your appointment with some fair colleen.

Not a hobbyist but my take on it from this companions point of view.

As of this writing I’ve only seen one Provider, though I’ve seen her multiple times.  As such, I’ve gotten to know her and genuinely like her; I’m not trying to make her my girlfriend or wife, but I do care for her (we’re becoming Friends with Arrangements maybe?)

Probably guys who have heard, or assume that the lady he just played with, can't look after herself. And there are plenty of arseholes amongst the good guys.  

it was a fun toy,
he wants the toy to be in the same condition, when it's time to play again.

is to admonish others to treat her right after realizing HE didn't, but he wants her to stay around so he can see her again.  But I agree with others that its most often a BSU move by a guy who plans on repeating.  For the record, I have NEVER put this in a review.  If guys don't know how to behave, the provider has her options.  I don't need to be the daddy with other hobbyists.   Also never said, "run, don't walk", it just sounds stupid.  I sometimes will mention a girl is leaving soon (if she told me) and if they want to see her, go sooner rather than later of they will miss out.

To those who don't suffer from the hardened hooker heart syndrome, it might rather be taken as an expression of endearment. I think the world would be better off with more such, not less.

...and that means I am feeling kindly towards the provider and think that as long as you treat her nice she will delay the almost inevitable slide into cynical, hard bitten disillusioned, mistreated whoredom where she treats her clients like meat because thats how the collective "they" have treated her over the years.  Its an adminishment to my peers to play nice because the gal is "nice" and I want her to remain that way.

...Roy Head told him if you treat her right she's gonna love you tonight. Check the link.

YMMV if you’re stuipid. I read that comment in reviews and assume it means “I personally had a great time with this woman, if you want the great experience I just had, don’t be stupid and you’re going to have a good time too”  

It is number one..........Imagine if you will.........you are a woman....you make your living providing pleasure to strange men....(many of whom are very strange) !  Don't be  Jerk.....treat this woman----who has just engaged in the most personal connection you can have with another human being.....with respect and be grateful that she is willing to participate and provide you with that connection.... and that once you and her have concluded your transaction....there is no ongoing relationship required by either party !  Be Nice !

Even I wrote it the first time I wrote a review.  Now I'm a veteran, and know that it goes without saying.  Except for the dumbfucks who don't know how to treat a lady.

I think it’s just a thing...

Treating her like your wife.

I have found that clients were truly hoping I had a good experience so I stick around. 80% of my clients have rebooked second appointments. I find when clients genuinely like who is a girl is beyond sex and looks they tend to say this. I think they truly just want us to be treated right.  

I have always taken it to mean the hobbyist had a good time and really liked the girl. Why read anything more into it than that?