And as you said, not every workshop is the right fit for every participant, and that's fine! In my case, if your workshop happened to be nearby, I'd probably go check it out "just cuz". I don't meet a lot of data viz people in my rural area (Central Oregon).
If it required travel, I'd gladly go if my employer would pay for it (they won't, because it's not relevant to my current job). For me to be willing to take a day off work and pay for travel expenses & registration fees myself, probably the only thing that'd get me to attend is what I mentioned already, namely real-world expertise from people who use D3 a lot, not a beginner's workshop. To be clear, I AM a beginner at D3, but I've used a lot of other charting solutions in the past, and I probably wouldn't attend a workshop just to learn the basics. I generally learn basic usage better from written tutorials, but I still enjoy real-life conferences if there are more advanced panels/discussions. The difference (to me) is that the advanced discussions are less "how-to"s and more "here's stuff you probably never even thought about... avoid these pitfalls".
Good luck with your workshop though, and thank you for running it! Sounds like a great opportunity for people who learn well that way.
