Ask HN: What does Paul Graham mean by this?

Within the written essay entitled growth,subsection "Rate" Mr.Graham mentions "The best thing to measure the growth rate of is revenue." Which is straight forward but,read on.. My startup: After obtaining 20-30 paying users & within 2 weeks without a dime spent on marketing I'm distributing the actual product to my users soon. My question is besides scaling through giving users a great product+ great experience,what else is suggested? Is that when I should start contacting bloggers? Those 20-30 users can spread to 100 users,but at one point it will stop. How would you suggest continuing user acquisition while gaining user feedback that scales rapidly?