BIG MISTAKE: "We're just going to do this for a few customers..."
When thinking about staying focused and avoiding working on the wrong things for the wrong customers and use cases, it's better to have ZERO or a LOT.
People who admit distraction into their org will often argue, "Oh, this is just for one customer" or "We're only going to do this for a few people" - as if this is some kind of virtue.
Having "just a few" is the WORST of BOTH worlds.
You get all the requirements and distractions and none of the scale.
Do it. Or don't do it.
If you're going to do it, plan to SCALE it aggressively.