While it has been years since I participated in this hobby, I am more an observer now, my preferances were going for massage. My thing was, I didn't really want to know if it would happen. I found it more erotic for me to enjoy the anticipation of wondering if a release of some sort would happen. Wondering as fingers slid up my thighs if they would go any further. Once I found someone who would provide this, I would see her a few more times, find myself getting bored and move on. It may sound strange to most of you but this is what floated my boat.
Point I am making is that I found that sometimes it took several visits to a massage provider for this to happen. I think some of them want to know you can be a trusted and regular client for this to happen. I had found several providers over the years that would give some extras as a favor to a regular client.
Now enjoying the hobby this way is not for everyone, obviously. But again, it was the anticipation that drove me, the not knowing. Once I knew what would happen, I lost interest.