I'm sure you've looked here already, but http://carbide3d.com/projects/ is a great starting point for ideas.
But here's my two cents:
I think what makes the Nomad (and desktop CNC in general) unique, is the fact that rapid personalisation is possible. Individual objects can be tailored quickly to the customers intent. And you don't have to start from scratch, almost any existing product can be engraved. I think the trick is to meet them halfway, come up with a product that would benefit from a unique touch. I sell stamps for weddings with a bit of my own design and get the customer to add their names and date. There's a big market for weddings.
Things that you could sell with someones name or logo engraved or embossed in/on is pretty much endless. Stationary, picture frames, signs, you name it.
Get them to input on the design, and you get two things: they feel invested so they're more likely to buy the thing, and they'll pay slightly more too because they appreciate a personalised product. Not too tricky to make something profitable that way.
It's true that you lose an element of impulse purchasing, as people have to leave an order with you and don't get to walk away with something in their hands. But if you're selling online then that effect is massively reduced. All customers would suffer is a longer delivery time. Also good for weddings because people plan those things way in advance.