It depends. I'm sure the people building YouTube thought it was a pretty dumb and costly idea. You could tell your client you don't think their project would

It depends. I'm sure the people building YouTube thought it was a pretty dumb and costly idea. You could tell your client you don't think their project would take off, but you never know unless and until you try. Also, why not give some guidance towards a small pivot in your perceived good project direction? Crass ideas like when it's about a new OS or something of the like you wouldn't take on anyway. Right?