I too would be skeptical until an actual product is delivered. But my skepticism is not just limited to companies with no history. How many times have 'the big boys & girls' promised the next big thing since sliced bread that would revolutionize the way one thinks and acts only to have their promised application/device be yawn inspiring or vapor-ware??

WRT the PO Box as Suite issue: Like it or not that is the way business is done even by legitimate small companies and start-ups. Not everyone can get enough venture capital together to rent office space even at one of the shared space type places. Maybe they work from home and don't want to use their home address for privacy reasons. Or maybe they see it as a waste of money to pay for shared-services when all they will use it for is as a mail drop. But the other side of that coin is exactly the attitude you displayed. IF they listed the address as PO Box XXX some would dismiss them simply because of that. I work for a Government agency and get to evaluate current and potential contract holders. I get to see a lot of things. I can tell you for a fact that just because an enterprise uses the PO Box as a Suite for mail delivery/contact information does not automatically mean that the enterprise is untrustworthy. By the same token it does not automatically mean that the enterprise is trustworthy.

Finally, wrt the enterprise specifically mentioned in this thread. I, personally, would not use the existing offering. I don't need to pay an extra fee to get roaming rates. I can get those sans extra fee. However, IF ... IF, the enterprise were to be able to demonstrate that the proposed product [multiple local rates through a single SIM] works, I would be much more inclined to try out the product even though the enterprise doesn't have a history. Afterall, isn't that part of the American dream? Work hard, be ingenious, come up with something new or a new [better] way of doing something old and getting rich from one's efforts.