Any concrete recommendations for building a SaaS or consultancy around a stack of open source tech with a given theme (anyone)? I whole heartedly agree, but then feel like a snake oil salesman without showing what it actually does as part of extending to what we want to do together. I do this perhaps as proof that I can deliver what I say, maybe that’s not an impulse that should be acted upon? Thanks.

"Just" is an important word in OP

The order of a sales pitch should be like this:

* here is the problem we wre trying to solve. Is this your problem, mrs. Customer?

* here is how our other customers were trying to solve the problem before they met us. Is this you, Mrs. Customer?

* here are the benefits of our product. If we could do all of this, would you want this product?

If you haven't moved them to a place where this hypothesis is true (if yes, then buy), no product demo in the world will help.

Then yes, by all means prove you can deliver what you say.

I generally dislike TLDRs, but yours is directly on point. It’s about focusing on the ‘job’ you want your product to be ‘hired’ for. This is what Clayton Christensen’s last book was about: https://www.goodreads.com/book/show/28820024-competing-again...

Yup, this is spot on. Not just for demos, but sales in general. It's not about you. It's about the customer and solving problems they care about.