A big driver of growth for a company of any stage is momentum.
There are roughly two types of momentum: internal and external. Both are very important, and often overlap.
I'd argue the internal piece is far more important, long term, than the external piece. You need your team to feel momentum. Why? They need to be excited about what they are doing.
Momentum is an energy felt in the room. It is a type of flow. While it may be hard to describe this exact sense, describing the opposite of momentum is quite easy as images quickly come to your mind.
You can already imagine a room of co-workers lacking momentum. They lack motivation. They are sluggish. You have to beg them to work on something. They are not pushing onward. Rather, they are stagnating.
Startups, in particular, need internal momentum to keep attention of their employees. Really any size company, but especially small ones, are fighting for passion.
Smart people can allocate passion to most problems and come up with solutions. Companies need momentum to convince their internal stakeholders that their particular solutions/problems that fit in their product are worth their attention. Win the attention of the internal team - and you can win long term.
External momentum is an important force in driving success and should be thought about. You can "fabricate" external momentum with things like press and paid ads. Long term, external momentum, however, is driven when you discover and solve for something that people really care about.
They must really care about it.
If you solve a real, tangible problem for someone - they will not only thank you - they will tell their friends. There will be hype around your product. Buzz. Excitement.
Things that no amount of PR and ad spend will be able to buy.
External momentum is very powerful, and leak into your internal momentum.
Regardless - keep pushing onwards.