This is a great summary! We really should write something like that in a whitepaper. Thanks for this.

Great question - this takes about 14 KB upload and 128 KB download per query. This is much more than for a normal address query, but on an absolute basis, it’s really small (less than just loading a page with a photo, for example). There is also a one-time upload for the first query of about 8 MB. As far as bandwidth, it would be usable even on a slow 3G connection. The main cost is really on the server side, since we have to maintain a fairly large server to answer queries. This is why we’re interested in building a service people would be willing to pay for, so we can cover these server costs.