I used to get paid for webcam and phone. It can be like prostitution but really depends on the relationship with the person paying. When it's not really much of a relationship at all, less so. But when that person wants to chat more and pay for bills or presents to gain exclusive material, it's essentially prostitution with the same level of "I need to do this request to keep him happy" and some requests can be really demeaning. One of the worst ones I heard was to choke myself until my gag reflex forced me to vomit.
I used to be paid for in person sex so I can tell you, that at least for me, there's very little difference.