[dspillett]

So the service is ad sponsored like those services? And is mining data to target that advertising? I can't see any of that, but if you explicitly compare yourself to that sort of service without specifying otherwise it is an assumption many will make and won't be happy with.

Without some obvious sign of how the service intends to fund itself a lot of people will walk away assuming that it is advertising and/or mining (which they won't like for their invoices), that it will go away as soon as some unknown reserve runs out, or that it will suddenly become expensive once they are dependent on it. They won't believe "we never intend to charge" (they've heard that before and it hasn't always been true) and won't email you to ask (they just head off on their merry way).