Yes money mainly, but I do get a thrill from it. Maybe not so much anymore but when I was younger and hopping around different countries and cities and feeling very liberated in many ways. I am a good brander now, and have good seo skills and stuff as a result, too.
Its made me a very autonomous person, which has positives and negatives, the negatives being now that I am 'institutionalized'... office work or whatever would be tough for me, so I do try and think about keeping my health and fitness now so I can maintain myself as a sex worker, if I have to, in theory, until retirement age (if state pensions still exist then!). Positive are though I don't have to put up with anyone's bullshit, bullying bosses, gossiping colleagues, unattractive working environments and tedious and unimaginative tasks for 50 hours per week.