One of the more common challenges that I run into when discussing the notion of async as the main communication mechanism is that there seems to be an entrenched belief that things should be synchronous. It appear to make things simpler, from a conceptual level, while making them significantly more difficult to actually implement them in a production worthy way.
Arguably the most common issue that I hear about is with downloadable materials, and it can be summed up as some variation of:
What do you mean we aren’t going to just start downloading stuff immediately?
That was why I was heartened when I tried to get a few Kindle books (ebooks) and saw that:
After about 5 minutes, it changed to this and allowed downloading this:
It is sad to say it, but applying to authority may suck as a argument tactic in a moral sense, but it is a damn effective one. Being able to say, here are all the reasons that you want to do that, and this is how Amazon is doing things, make it so much easier to sell this approach.