A lot of startups rightly aim to release a minimum viable product (MVP) as their first initiative. The goal of an MVP helps a team rally around a concrete product design that they can get out the door in a limited amount of time. And it's every startup's hope that once the MVP is released, early adopters will flock to it eagerly and tell their more mainstream friends by the millions.
When most MVPs get released, however, this dream doesn't exactly pan out. Instead of experiencing healthy growth and engagement, the MVP gets tepid interest from the market. It's neither an entire flop, since there are people who adopt it and do seem to like it quite a bit. Nor is it a clear success, since these people number in the hundreds or thousands, and their numbers don't appear to grow very quickly.
At this point in the startup's lifecycle, it faces a fork in the road wherein it can decide just what to do about its MVP. Most startups think to themselves: "OK, it looks like we have the beginning of something interesting even if it's not an instant hit. If we just iterate on the core product and make it incrementally better, we'll hopefully get it to the point where its value to the ordinary user reaches an inflection point and our active users will take off."
This is a very dangerous mindset to adopt post-MVP, because you're inherently conceding that your minimum viable product was, well, unviable. But you're also skirting that reality in practice. If the MVP contained the most important kernel of the experience you were hoping to provide users and that kernel itself didn't get most people who tried it excited (judged primarily by your retention rate), then your fundamental thesis was wrong. Adding extra features, design refinements, and performance enhancements on top of the MVP is not going to change the main lesson you've already learnt, which is that the core concept you've released does not resonate with the market you had in mind.
The other path, which far fewer startups take upon releasing their MVP to an unenthusiastic market, is to stop and honestly assess what they've already attempted with it. Instead of going head-first into a mode of iteration, startups on this path critique their MVP's core experience and develop hypotheses as to why it wasn't found compelling enough by the market that tried it. These startups either attempt the same MVP with a significantly different market, having decided that the one they initially approached didn't have matching needs. Or they stick to the same market and revamp the fundamentals of their product, essentially going back to the drawing board.
Inertia is the reason you don't see many startups make this hard decision to question the essence of their market or product. And this inertia is often created by a whole host of factors, such as founder vision, investor and employee buy-in, and press exposure. When you're running product for a startup, it's much easier to stay headstrong about your initial concept and ignore clear market feedback, since one perceives it as too difficult to reorient the entire game plan and messaging for the product (I was certainly guilty of this with Plancast). It's also relatively easy to rationalize that the market simply needs more time to come around, or that just a couple more features will make it "click" with people, especially if you have money in the bank and supportive advisors who don't want to dampen your enthusiasm for it.
But the bravest and most critical thing that product managers at startups can and must do is treat their products as the experiments they are, maintaining a critical and detached eye for what they're building, at least until those products reach a pace of undeniable growth and engagement that makes it clear a market clamors for them.