My friends and I are considering building bitcoin ATMs. We're still doing the necessary research and planning and we've been looking at existing ATMs like Lamassu. Based on what they've been reporting online (and other sources), it seems to be a pretty profitable business.

We understand that there are lots of regulations involved depending on the country of residence, but we are considering just building and selling the machines, not operating them. Off the bat, are there any other important considerations we should know? Red flags? Any feedback will be appreciated.