I agree with how market positioning is so important to a startup, and yeah I kinda respect KISSmetrics for having the guts to do this. My anger really came because I felt they'd cut off the bottom of the ladder where those of us who can't justify $150/month on analytics where standing. And this was a surprise because nothing until the pricing announcement indicated that this was the direction they were going to take.
It is intrinsically hard to attribute improvements in conversion rate to a single cause, except in an A/B test. It will be sensitive to changes in the traffic mix, seasonality, strategic decisions, etc etc.