Loved this post by Hiten Shah on how some of the best companies innovate by copying.
Amplitude's mobile analytics platform serves as one of his biggest examples. They've been taking Mixpanel's customers for years, not by trying to do anything radically different, but simply by "giving away the same thing that Mixpanel charges $1,000 a month for." Where Mixpanel limited you to 25,000 events per month on the free plan, Amplitude gave you 10,000,000. So for Mixpanel customers who valued the ability to track more and more events had a really great reason to switch.
The other half of the equation, though, is what you do once you've "succeeded" at copycatting someone else's model or undercutting them.
Mixpanel has (sometime in the last few months) totally revamped their pricing, now giving you 20,000,000 events or data points on their free plan. They're conceding, in a way, that Amplitude was right to look at events as a big value metric for customers.
If Amplitude had done nothing but copycat Mixpanel, there would be nothing stopping their customers from all going back to Mixpanel now -- where you can now get the most events for free.
That's why Amplitude's diving into behavioral analytics and data accessibility is so important. Where Mixpanel succeeded by showing people that "active" users were more important than "registered" users, Amplitude draws deeper distinctions within the idea of activity both in how they talk about analytics and how they build their product. They're not just selling you a cheaper version of Mixpanel -- they're selling you a qualitatively different kind of outcome from your study of your analytics. They're selling you something that's smarter -- and now that Mixpanel's undercut them on price per event, that's exactly what they need to be selling.