Okay I'm just going to add my two cents into this.
Yes some woman do just want an easy way to make some money. These woman 9 out of 10 times go to high end escort services. And most of these high end escorts are ran by women. They pay the services a percentage for finding them work and keeping them safe. These types of woman don't usually get involved with actual pimps.
Now, the girls who end up on the streets with pimps and working off of craigslist are typical not doing it for the money but yet doing to keep up with their drug habit.
I've seen it with my own eyes. I grew up watching these things happening every day. It's actual pretty simple to see. I am one of the lucky girls that was smart enough to watch and see how this happens and some how never ended up a victim and was able to get to college and better my life and end up in a nice home. But not all these girls are that lucky.
I would sit and watch these pimps who are most times also drug dealers. What they would do is target younger girls 15, 16, 17 and so on.....most of the time these girls were in fact very vulnerable and insecure (seems they can sniff the insecurity out like blood hounds). They would be all chummy with these woman never once saying they wanted them to prostitute. Most the time these young girls don't even know they are pimps these young woman are very naive. And most times these woman are not addicted to drugs. They are simply looking to belong. Or are not getting attention from boys there own age and take what they can get. Some are also run aways either from a bad family and I've also seen some from really good familys but they feel out of place and their parents are simply to strict and they rebel. So they hang out for while and party with these guys. Beer is always free for the ladys and most importation the drugs are ALWAYS free. But after smoking blunts and drinking beers for a few weeks they start to introduce these girls to cocaine or crack. They supply these drugs for free for weeks. After about a month these girls need to have the drug. The girl shows up expecting the same as before but this time they are told they need to start earning their drugs. So then they start to Prostitute. And that my friends are how pimps in the hood work. I've seen it so many times. I've lost a lot of good friends who never had done drugs and would never dream of being a prostitute to these pimps.
I've also seem some pimps go after lonely older woman. It does happen. I think it's pretty naive to say and just think that most these girls just want to make an easy dollar. That is not true.
And I bet you if you were to ask these pimps how they work they would tell you. They sit and laugh about it. I've had them try to do it to me. They get the girls hooked on purpose on drugs just to turn them into prostitutes. This way they are able to make money off them and keep the girls happy. But the girls start to catch on and get unhappy and by this time they are stuck. They are being threatend, and beat up. It's actually very easy to put the fear of god into young woman. I my self have been in fear of these pimps and I wasn't even a girl they "owned". The only way to get away and to live with out fear is to move far away. But how do you do that when you are young, scared, don't know where to go and of course have a child now from one of the pimps or johns? Not only that but you have no money to leave because these pimps give you just enough for cigs and a few other things.
You are talking about streetwalkers there mostly. The craigslist bunch on average are more freelancers, because anyone with access to a computer and a phone can do it, and do so relatively discretely (something you can't do patroling the streets since everyone can see what you are). This is the reason for the explosion in prostitution in recent years. It is so easy for girls to do it with little risk, unless they get caught up in an LE sting or by a psychopath (both of which are fairly rare occurrences). On the street a pimp can spot the girls right away and intimidate them if they don't allready have that sort of protection, but operating from craigs list the girls are more insulated - pimps don't know who they are, or if they have protection allready.