Million Answers
 lol
And Yes There are many reasons..
For Starters  
SEX AND MONEY  

I know three who started out as sugar babes and dipped their toes into the profession.  Only one continued to find success as a pro.  The others found they couldn't get enough biz fast enough or it didn't fit their lifestyle.
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I'm not sure what percentage of SB's will consider becoming pros.  I suspect is just a small percentage.

1) Dancing, then exotic dancing, then the champagne room

My understanding is the Sugar Daddy is more socially acceptable. She's not the W word or hooker, but some old guy wants to take care of me, and that is socially acceptable. Especially if its gifts, jewelry, car, or other things than just straight cash. Think Hugh Hefner of Playboy. You get to stay in a nice mansion, you get 'paid' indirectly through a photo shoot, so you're not a hooker, but a Playboy Model.  Fine line between dinner date, gifts, flowers, and just being given straight up cash to sleep with a guy.

I don't think most SB's go with any guy with money ... or at least with guys not willing to throw endless money at them.  But if you have endless money I would stick with pros.  

Maybe w. escort girl has more independent and do her own things whereas SB she may feel like she is "owned".

and I hate to burst your bubble, but most of them want cold hard cash. Just like a hooker, only they play mind games with themselves in order to convince themselves that they aren't "cheap dirty hookers" as if being a hooker is a bad thing. I LOVE hookers, but I also LOVE SB's, come to think of it, I LOVE sluts and whores too. lol

As BP says, they do like gifts other than cash, but as you say, not instead of cash.. As you state, I think getting other gifts once in awhile makes them feel like they are a cut above hookers, so its just like you say, they are grasping at straws to NOT feel like prostitutes, but these gifts are above and beyond the agreed cash stipend.  When I comes to service, they just can't compete with hookers, IMO.  

Hmmmm, didn't mean it to read "instad of" cash, but that gifts are welcomed and accepted IN ADDITION to cash. Obviously they are in it for the money, they just don't want to feel like cheap whores. Nor does the vast majority of women for that matter. You can do all sorts of things to women, as long as you don't make them feel cheap and easy.

CD, I think the Rolex question goes squarely in the why not ask, it can't hurt. The worst he can say is no. The best outcome is I get a Rolex. Actually the worst outcome was in her face, that you would tell her to take a hike and the candy ride would end, so she shut up.