I just want to reinforce cperciva's last point. My observation of 100+ startups that I have worked with or known well is that the growth of a single product oft

I just want to reinforce cperciva's last point. My observation of 100+ startups that I have worked with or known well is that the growth of a single product often peaks at year 4 or 5. After that, it tails off. Good companies are the ones that keep the innovation going so that there is a new product that continues to drive value for the company around that time. Apple is probably the most obvious and clear example of this (iPod - 2001, iPhone - 2006, iPad - 2010), but the pattern holds true in many software companies I know.