What’s the best way to measure product usage?

Paul Graham (Co-Founder & Partner at Y Combinator)
Startup = Growth

A good growth rate during [Y Combinator] is 5-7% a week. If you can hit 10% a week you’re doing exceptionally well. If you can only manage 1%, it’s a sign you haven’t yet figured out what you’re doing. We usually advise startups to pick a growth rate they think they can hit, and then just try to hit it every week.